An integrated simulation and optimization modelling environment for decision support

This paper discusses the initial steps towards the formulation and implementation of a generic and flexible model centric framework for integrated simulation, estimation, optimization and feedback control of polymerization processes. For the first time it combines the powerful capabilities of the automatic continuous on-line monitoring of polymerization system (ACOMP), with a modern simulation, estimation and optimization software environment towards an integrated scheme for the optimal operation of polymeric processes. An initial validation of the framework was performed for modelling and optimization using literature data, illustrating the flexibility of the method to apply under different systems and conditions. Subsequently, off-line capabilities of the system were fully tested experimentally for model validations, parameter estimation and process optimization using ACOMP data. Experimental results are provided for free radical solution polymerization of methyl methacrylate.

Question retrieval aims to increase the accessibility of the community Question Answer (cQA) archives and has attracted increasing research interests recently. In this paper, we present a novel method for improving the question retrieval performance by investigating the question term selection and weighting as well as reranking results. Different from previous work, we propose a hierarchical question classification method with a sparse regularization to mimc user's question labeling in cQAs. Based on the hierarchical classification, we explore the local context of the question for term selection and reranking results and then integrating them into our proposed general question retrieval framework. The experimental results on a Yahoo! Answers dataset show the effectiveness of our method as compared to existing general question retrieval models and some state-of-the-art methods of utilizing category information for question retrieval.

Simulation of Technological Processes in Coal Mining

An object-oriented architecture for extensible structural design software

This paper describes the design and implementation of a prototyping, analysis, simulation, and synthesis environment called PASS for real-time application systems. The design of the PASS environment is based on an event-driven model, whereas certain timing constraints such as period are described implicitly. The PASS environment supports not only detection of possible violations of end-to-end delay requirements but also a way to verify important system properties such as the bound for the error propagation problem. The strengths of this work were demonstrated by a case study on a common chalkboard example over Ethernet.

This chapter discusses the challenges of creating an instruction set simulator (ISS) and system modeling environment for configurable, extensible processors. Processor generation technology is highly automated and is used by designers to create application-specific instruction set processors (ASIPs) targeted to specific application domains. The main challenges for creating an ISS lie in the configurable and extensible nature of the processor, which is tailored by designers at design time, not fixed in advance. Thus simulation models need to be created on the fly when designers have configured a new version of the processor. They need to be created automatically and offer good performance with a variety of use modes. In addition, multiple speed-accuracy trade-offs are necessary to support these various use modes, such as instruction-accurate, cycle-accurate, and pin-level. Furthermore, these ISS models must themselves fit into system modeling and simulation environments, both generated along with the ASIP and commercial third party ESL/EDA tools. Again, multiple use models and trade-offs in simulation scope, speed, and accuracy must be supported. Standards to ease integration and model interoperability in this area have arrived only recently and are just beginning to make life easier for model providers.

Dedicated bus lane (DBL) and transit signal priority (TSP) are two effective and low-cost ways of improving the reliability of transits. However, these strategies reduce the capacity of general traffic. This paper presents an integrated optimization (IO) model to improve the performance of intersections with dedicated bus lanes. The IO model integrated geometry layout, main-signal timing, pre-signal timing and transit priority. The optimization problem is formulated as a Mix-Integer-Non-Linear-Program (MINLP) that can be transformed into a Mix-Integer-Linear-Program (MILP) and then solved by the standard branch-and-bound technique. The applicability of the IO model is tested through numerical experiment under different intersection layouts and traffic demands. A VISSIM micro simulation model was developed and used to evaluate the performance of the proposed IO model. The test results indicate that the proposed model can increase the capacity and reduce the delay of general traffic when providing priority to buses.

The rapid development of urbanization brings a lot of problems, and the protection of the heritage of historical and cultural districts needs to formulate the protection strategy according to the local environmental adaptation and continuously improve and amend it. In this paper, a model is developed for the environmental adaptation mechanism of the heritage of historical and cultural districts, and the spatial structure of the heritage of historical and cultural districts is calculated using spatial statistical methods. Subsequently, an environmental calculation simulation model is proposed based on ENVI-met software, which combines the spatial structure to simulate and analyze the environment of the Shengjin Tower Historical and Cultural District Heritage in Nanchang City, and analyze its environmental adaptability. The test results show that the environmental simulation model proposed in this paper can accurately simulate the environmental change values of the heritage of the historical and cultural district according to the values of external environmental factors. The results of the analysis of the Shengjin Tower Historical and Cultural District Heritage show that the plots in the districts have an average thermal environment adaptation degree of 1.02, and the average air environment adaptation degree is 1.08. Meanwhile, West Street shows higher performance in air environment adaptation degree, with an average of 1.10. The adaptive degree of the plots in the downwind direction is poor, and they are easily affected by the external environment. This paper lays the foundation for other studies on the environmental adaptation of heritage in historical and cultural districts, and the conservation strategies proposed in terms of symbiosis, wholeness, and dynamic sustainability provide references for the conservation and inheritance of heritage in historical and cultural districts.

Grey mould (Botrytis cinerea) is one of the most severe diseases in greenhouse crops. For its control, humidity is kept low and chemical and biological control agents are used. An early warning system for disease outbreak likelihood would help to improve B. cinerea management. In greenhouses with model-based climate control there is scope for automatic humidity control to manage B. cinerea in trade-offs with other production parameters, such as energy saving and product quality. In the present paper a mathematical simulation model for Botrytis was developed as basis for greenhouse climate control. The model was designed from literature studies and implemented in a software simulation environment. The model consists of two components representing (1) crop microclimate and (2) disease development, including the complete life cycle of Botrytis cinerea from mycelium and spore development to sporulation and spore deposition on the susceptible plant parts. The model calculates durations of leaf wetness and leaf dryness in order to predict the success rate of spore penetration and thus infection. The model was parameterised for the cut flower Gerbera. The model was connected to a greenhouse climate simulator and in general form. Simulations were performed for a standard glass greenhouse located in The Netherlands using a reference climate year. The developed model for Botrytis control presents a novel design that creates a possible basis for a future climate regime to control Botrytis in greenhouses with a strong reduction of chemical biocide use.

The article introduces a new universal software environment for multi agent simulation. The environment presents the model of reality and it is suitable for testing of the existing or new methods, especially in the field of agent coordination, cooperation or collaboration. The software is aimed to be used in any Java based simulation tool and to provide a consistent approach for gathering comparable results among these tools. Moreover, it can be applied in problems such as coordinated decision making, attitude alignment problem, robot position synchronization, dynamic obstacle avoidance and more others. The concept of this tool helps to create programs which are easily transferable and applicable to real robotic platforms.

An optimization of the energy consumption in network systems has been recently an important research issue. The main challenge is to design, develop and test novel technologies, integrated control strategies and mechanisms for network equipment enabling energy saving by adapting network capacities and resources to current traffic loads and user requirements, while ensuring end-toend Quality of Service. In general, the idea is to develop low power devices or nano-processors, concentrate network traffic on a minimal subset of network components, and modulate network devices using dynamic voltage and frequency scaling methods. Various power adapting technologies for network devices are described in literature. We developed a framework for a backbone network management which leads to the minimization of the energy consumption by this network. The concept is based on activity control of the network equipment. The framework is presented in (Niewiadomska-Szynkiewicz et al., 2012b). In this paper we describe the design, performance and potential applications of the software environment for energy efficient backbone network optimization and simulation. This system was used to illustrate the performance of our control framework for energy-aware IP networks.

Design and Simulation of Heterogeneous Control Systems using Ptolemy II

We present the VECMA toolkit (VECMAtk), a flexible software environment for single and multiscale simulations that introduces directly applicable and reusable procedures for verification, validation (V&V), sensitivity analysis (SA) and uncertainty quantication (UQ). It enables users to verify key aspects of their applications, systematically compare and validate the simulation outputs against observational or benchmark data, and run simulations conveniently on any platform from the desktop to current multi-petascale computers. In this sequel to our paper on VECMAtk which we presented last year [1] we focus on a range of functional and performance improvements that we have introduced, cover newly introduced components, and applications examples from seven different domains such as conflict modelling and environmental sciences. We also present several implemented patterns for UQ/SA and V&V, and guide the reader through one example concerning COVID-19 modelling in detail.This article is part of the theme issue ‘Reliability and reproducibility in computational science: implementing verification, validation and uncertainty quantification in silico’.

The authors described the architecture of a cellular automaton used as a hardware accelerator in the evaluation loop or a genetic algorithm (GA). Cellular automata are basic computational structures of interacting units which are capable of exposing self-organization and emergent behavior. To investigate this behavior subject to different cell interconnect patterns, an automated inspection flow is needed, including a very fast evaluation of single specimen. The solution consists of a distributed software environment for a parallel simulation, where server processes can encapsulate a hardware accelerator instead of a software simulation. Here the focus is on the hardware implementation: a flexible FPGA-based accelerator for cellular automata evaluation which is accessed transparently by a GA Java client. First results show moderate area requirements allowing an FPGA implementation and a clock frequency of up to about 130 MHz raw transition performance.

The computer simulation of the injection phase in resin transfer molding (RTM) can help the mold designer to properly position the injection ports and the air vents, to select an adequate injection pressure, and to optimize the cycle time. The purpose of this article is to present RTMFLOT, an integrated software environment especially designed for the numerical simulation of the resin transfer molding (RTM) process. The main program modules are DATAFLOT, to evaluate the permeability of the preform, MESHFLOT, to produce a finite element mesh of the mold, FLOT, to compute the succes sive positions of the resin front, VISUFLOT, to visualize the numerical results, and HEATFLOT, to analyze the heat transfer phenomenon. The application of RTMFLOT to the design of a lawnmower hood is described in order to illustrate the various stages of the simulation process.