Proposed Simulation Environment Research Articles

Integrating OpenAI Gym and CloudSim Plus: A simulation environment for DRL Agent training in energy-driven cloud scaling

Experimentation in real cloud environments for training Deep Reinforcement Learning (DRL) agents can be costly, time-consuming, and non-repeatable. To overcome these limitations, simulation-based approaches are promising alternatives. This paper introduces a specialized simulation environment that integrates OpenAI Gym, a popular platform for reinforcement learning, with CloudSim Plus, a versatile cloud simulation framework. The proposed simulator specifically focuses on the case study of energy-driven cloud scaling. By leveraging the strengths of both Python-based OpenAI Gym and Java-based CloudSim Plus, the simulation environment offers a flexible and extensible platform for DRL-Agent training. The integration is facilitated through a gateway that enables seamless interaction between the two frameworks. The simulation environment is designed to support the training process of DRL agents, enabling them to tackle the complexities of cloud scaling in an energy-aware context. It provides configurable settings that represent various cloud scaling scenarios, allowing researchers to explore different parameter configurations and evaluate the performance of DRL agents effectively. Through extensive experimentation, the proposed simulation environment demonstrates its functionality and applicability in measuring the performance of DRL agents with respect to energy-driven cloud scaling. The results obtained from the case study validate the effectiveness and potential of the simulation environment for training DRL agents in cloud scaling scenarios. Overall, this work presents a novel simulation environment that bridges the gap between DRL-Agent training and cloud scaling challenges, offering researchers a valuable tool for advancing the field of energy-driven cloud scaling through reinforcement learning.

배전계통 정전복구 연구를 위한 연동 시뮬레이션 환경 구축

Faults of components on distribution networks result in electricity interruptions for all loads downstream of a faulty zone since distribution networks have been generally operated in radial structures due to simple design, low cost, and simple protection coordination. To restore the outage loads in the healthy areas, service restoration should be taken by using normally open switches to transfer the loads to other feeders. This paper proposes a co-simulation environment for service restoration studies composed of sub-simulation tools, OpenDSS and MATLAB, which enables distribution network modeling, power flow analysis, constraints check, generating service restoration candidates, etc. Multiple case studies on IEEE 37-node system are conducted under the proposed simulation environment in order to verify its performance and it is shown that the proposed environment is effective for the service restoration studies.

Analysis of Dual-Band Direction of Arrival Estimation in Multipath Scenarios

The present paper analyzes the performance of localization systems, based on dual-band Direction of Arrival (DoA) approach, in multi-path affected scenarios. The implemented DoA estimation, which belongs to the so-called Space and Frequency Division Multiple Access (SFDMA) technique, takes advantage of the use of two uncorrelated communication carrier frequencies, as already demonstrated by the authors. Starting from these results, this paper provides, first, the methodology followed to describe the localization system in the proposed simulation environment, and, as a second step, describes how multi-path effects may be taken into account through a set of full-wave simulations. The latter follows an approach based on the two-ray model. The validation of the proposed approach is demonstrated by simulations over a wide range of virtual scenarios. The analysis of the results highlights the ability of the proposed approach to describe multi-path effects and confirms enhancements in DoA estimation as experimentally evaluated by the same authors. To further assess the performance of the aforementioned simulation environment, a comparison between simulated and measured results was carried out, confirming the capability to predict DoA performance.

On the Benefits of Using Object-Oriented Programming for the Objective Evaluation of Vehicle Dynamic Performance in Concurrent Simulations

Assessing passenger cars’ dynamic performance is a critical aspect for car industries, due to its impact on the overall vehicle safety evaluation and the subjective nature of the involved handling and comfort metrics. Accordingly, ISO standards, such as ISO 4138 and ISO 3888, define several specific driving tests to assess vehicle dynamics performance objectively. Consequently, proper evaluation of the dynamic behaviour requires measuring several physical quantities, including accelerations, speed, and linear and angular displacements obtained after instrumenting a vehicle with multiple sensors. This experimental activity is highly demanding in terms of hardware costs, and it is also significantly time-consuming. Several approaches can be considered for reducing vehicle development time. In particular, simulation software can be exploited to predict the approximate behaviour of a vehicle using virtual scenarios. Moreover, motion platforms and detail-scalable numerical vehicle models are widely implemented for the purpose. This paper focuses on a customized simulation environment developed in C++, which exploits the advantages of object-oriented programming. The presented framework strives to perform concurrent simulations of vehicles with different characteristics such as mass, tyres, engine, suspension, and transmission systems. Within the proposed simulation framework, we adopted a hierarchical and modular representation. Vehicles are modelled by a 14 degree-of-freedom (DOF) full-vehicle model, capable of capturing the dynamics and complemented by a set of scalable-detail models for the remaining sub-systems such as tyre, engine, and steering system. Furthermore, this paper proposes the usage of autonomous virtual drivers for a more objective evaluation of vehicle dynamic performances. Moreover, to further evaluate our simulator architecture’s efficiency and assess the achieved level of concurrency, we designed a benchmark able to analyse the scaling of the performances with respect to the number of different vehicles during the same simulation. Finally, the paper reports the proposed simulation environment’s scalability resulting from a set of different and varying driving scenarios.

Simulation Of Haulage Systems Using A Flexible Simulation Environment

Abstract Simulation has been used for decades in the mining industry to improve the design of haulage systems and optimize their operations. There are in the market many simulation environments for carrying out these tasks. Despite the existence of these advanced tools, there is a need of having more flexible environments that could be easily integrated with other tools such as optimization, advanced data analysis and real-time systems. In this work, the use of SimEventsTM is explored to build basic models of the main components of a haulage system. Using the unique abstraction mechanism of this environment, the main components are programmed as blocks that can be used to configure mining haulage systems. A hypothetical open-pit haulage system is simulated using Arena and the proposed simulation environment. Several simulation scenarios are used to compare the different features of these simulation tools and demonstrate the flexibility of the SimEventsTM models to address different operational scenarios including the integration of dispatching and maintenance operations. In addition, these models, unlike the Arena ones, have the potential to be seamlessly integrated with other MatlabTM toolboxes for optimization and analysis.

Modelling and assessing the impact of the DSO remuneration strategy on its interaction with electricity users

This paper presents a simulation-based methodology for assessing the impact of employing different distribution system operator’s remuneration strategies on the economic sustainability of electrical distribution systems. The proposed methodology accounts for the uncertainties posed by the integration of distributed electricity generation resources, and the roll out of smart meters. The different remuneration strategies analysed in this paper include notably new distribution tariffs based on individual peak power consumption and time-dependent rates that are contingent on the time of energy consumption, both requiring smart meters to work. The distributed electricity generation resources are modelled through an optimisation framework and an investment decision process that gradually deploys household photovoltaic installations depending on their profitability and the electricity charges, including the distribution rates. The impact of the distribution system operator’s remuneration strategy is measured by an accurate modelling of the remuneration mechanism of this entity, which can adapt to various distribution tariff designs. We analyse this impact over a discrete time horizon. Our methodology is illustrated with several examples of distribution tariffs including old –based on energy consumption or on per-connection fees– as well as new –based on power consumption or time-of use fees– designs. Finally, we provide a comprehensive sensitivity analysis of the proposed simulation environment to the main parameters of the methodology.

A simulation model for train movements in the rail network

In rail transportation, the process of finding the optimal movement of freight goods is considered a tactical level of rail planning. Solving this problem requires one simultaneously to address the railroad blocking problem and the train dispatching problem, which is difficult. Additionally, when these problems are represented by mathematical relations, application of the solution leads to unexpected results in the real world. The main objective of this research was to build a simulation environment to represent the key behaviours of typical and applicable constraints of a railway system. This environment provides a tool with which to evaluate different decisions among a list of candidate decisions associated with blocking and dispatching problems. Since the movement of freight trains involves conflicting measures of effectiveness that need to be optimised at the same time, comparisons among decisions must be made in the presence of trade-offs between the different measures. The proposed simulation environment was used to analyse train movement in a case study of the Iranian rail network.

Analytical simulator of proton radiography and tomography for different detector configurations

PurposeAn analytical simulator of ion Radiography (iRad) and Computed Tomography (iCT) for protons is proposed to serve as imaging benchmark for different detector configurations. MethodsThe analytical simulator is applied to an anthropomorphic phantom and provides iRad and iCT benchmarks. Proton trajectories are traced relying on the Most Likely Path (MLP) algorithm. To simulate the proton trajectories the Multiple Coulomb Scattering (MCS) model embedded in the MLP algorithm is extended to non-uniform water equivalent materials according to variable substitution in the well-known statistical description in uniform water. The proton trajectories are instead estimated relying on the typical assumption of uniform water, thus causing intrinsic inaccuracies of the MLP algorithm. In this work the analytical simulator is used to explore and firstly compare the imaging performances of list-mode and integration-mode detector configurations with proton pencil beam scanning. ResultsThe intrinsic inaccuracies of the MLP algorithm affect the imaging performances of list-mode detector configuration, which nevertheless remains superior to integration-mode detector configuration for iCTs. For relatively higher proton statistics, comparable or better imaging performances are offered by integration-mode detector configuration for iRads (upto 29.2% of WET difference). Uncertainties of proton trajectories due to beam spot size are shown to compromise the imaging performances of integration-mode detector configuration, but also to affect the accuracy of the MLP algorithm for list-mode detector configuration. ConclusionsBased on MCS model in non-uniform water equivalent materials, the proposed simulation environment can serve for development and testing of dedicated imaging methodologies prior to and in combination with realistic Monte Carlo simulations.

Vehicular Network Simulation Environment via Discrete Event System Modeling

A vehicular ad-hoc network (VANET) enables vehicles to communicate with each other directly or via roadside infrastructure in order to improve road safety and efficiency. Within a VANET, communications can potentially alter vehicular mobility and conversely, that the mobility could potentially influence vehicular communications. Therefore, a VANET simulator environment is needed that can accurately model interactions between vehicular mobility and network protocols. In this paper, we present a novel vehicular network simulation environment designed using the MATLAB discrete event system (DES) in the SimEvents toolbox. The proposed simulation environment is a bit-accurate, discrete event simulator that integrates vehicular mobility operations with wireless network communication. This paper provides details on the design of the proposed simulator. Its computational costs are evaluated in terms of events quantities and execution time. The physical (PHY) layer of the proposed simulator shows a more realistic packet success rate (PSR) using bit-level processing techniques when compared with the packet-based NS-3 simulator. The performance of the priority-based media access control (MAC) layer proves the data with different priorities that can coexist in the same channel.

A COMPARATIVE STUDY OF QOS OVER IPV4/IPV6 USING OPNET MODELER

The increasing number of internet users around the world and their demand for multimedia applications like VoIP and video conference force the network providers to think about Quality of Services. Since these new applications are sensitive to network performance, the demand for larger bandwidth is increased especially when network parameters like Jitter, End to End (E2E) delay and Packet loss play a very important role to guarantee such application in terms of quality. In such environment, Quality of Service (QoS) is considered to be the most important network performance parameter which has a significant effect on multimedia applications like Voice Over Internet Protocol (VoIP) and others. internet protocol IPv6 was designed to improve QoS supported by internet protocol IPv4 and to enhance the reliability of packet based network to handle such services. This paper considered three queuing systems which are First In First Out (FIFO), Priority Queuing (PQ) and Weighted Fair Queuing (WFQ) as a comparative study to investigate their effects on real-time applications in IPv4 and IPv6 networks support. The proposed simulation environment was executed by Optimized Network Engineering Tools (OPNET) Modeler 14.5 where the simulation results are collected and analyzed. The results show that IPv6 with PQ provides better performance for real-time applications, despite that IPv6 with WFQ is more efficient with low priority traffic.

Agent-based simulation with NetLogo to evaluate ambient intelligence scenarios

In this paper, an agent-based simulation is developed in order to evaluate an Ambient Intelligence scenario based on agents. Many AmI applications are implemented through agents but they are not compared with any other existing alternative in order to evaluate the relative benefits of using them. The proposed simulation environment analyses such benefits using two evaluation criteria: First, measuring agent satisfaction of different types of desires along the execution. Second, measuring time savings obtained through a correct use of context information. In this paper, an existing agent architecture, an ontology and a 12-steps protocol to provide AmI services in airports, is evaluated using the NetLogo simulation environment. In our NetLogo model, we are considering scalability issues of this application domain but using FIPA and BDI extensions to be coherent with our previous works and our previous JADE implementation of them. The NetLogo model simulates an airport with agent “passengers” passing through several zones located in a specific order in a map: passport controls, check-in counters of airline companies, boarding gates, and different types of shopping. Although the initial data in each simulation are generated randomly, and the model is just an approximation of real-world airports, the definition of this case of use of AmI through NetLogo agents opens an interesting way to evaluate the benefits of using AmI, which is a significant contribution to the final development of AmI systems.

EXTRACTING ACTIONS FROM INSTRUCTION MANUAL AND TESTING THEIR EXECUTION IN A ROBOTIC SIMULATION

Service robots are expected to execute household manipulation tasks on daily basis. These tasks are often related to the operation of home appliances and can be decomposed into specific manipulation actions such as pick up a cup, place a cup, press a button, turn a knob, open or close a cover, etc. This research proposes to use task instructions collected from manuals of household appliances to extract a series of actions that a robot needs to perform in order to accomplish the task. We describe the extraction method of action and object from these task instructions including syntax parsing of sentences and searching the pairs of action and object in each parse tree based on part-of-speech. The extracted actions then will be executed by a robot. We apply a simulation environment with ROS, Gazebo simulator and a virtual robot PR2 for testing their execution. In experiments, we implement the extraction method and evaluate the extracted results of actions and object. In addition, we test the execution of actions pick and place in the proposed simulation environment.

Analysis of wheel speed vibrations for road friction classification

ABSTRACTWith higher level of vehicle automation, it becomes increasingly important to know the maximum possible tyre forces during normal driving. An interesting method in this respect is estimating the tyre–road friction from the resonance peak in the wheel speed signal, excited by road roughness. A simulation environment using the MF-Swift tyre model is proposed, which gives insight in the correctness and functioning of this method. From implementing the estimation algorithm and considering the tyre torsional vibration system, it is concluded that frequencies and damping ratios can be estimated with reasonable accuracy and that the trends observed with changing road friction are consistent. Furthermore, the proposed simulation environment gives opportunity to investigate other issues like robustness of the estimation method to road roughness. Additionally, the tyre modelling aspect of the estimation method is analysed and improvements are proposed.

A Simulation Environment for Benchmarking Sensor Fusion-Based Pose Estimators.

In-depth analysis and performance evaluation of sensor fusion-based estimators may be critical when performed using real-world sensor data. For this reason, simulation is widely recognized as one of the most powerful tools for algorithm benchmarking. In this paper, we present a simulation framework suitable for assessing the performance of sensor fusion-based pose estimators. The systems used for implementing the framework were magnetic/inertial measurement units (MIMUs) and a camera, although the addition of further sensing modalities is straightforward. Typical nuisance factors were also included for each sensor. The proposed simulation environment was validated using real-life sensor data employed for motion tracking. The higher mismatch between real and simulated sensors was about 5% of the measured quantity (for the camera simulation), whereas a lower correlation was found for an axis of the gyroscope (0.90). In addition, a real benchmarking example of an extended Kalman filter for pose estimation from MIMU and camera data is presented.

Network design and planning of wireless embedded systems for industrial automation

The widespread adoption of wireless systems for industrial automation calls for the development of efficient tools for virtual planning of network deployments similarly as done for conventional Fieldbus and wired systems. In industrial sites the radio signal propagation is subject to blockage due to highly dense metallic structures. Network planning should therefore account for the number and the density of the 3D obstructions surrounding each link. In this paper we address the problem of wireless node deployment in wireless industrial networks, with special focus on WirelessHART IEC 62591 and ISA SP100 IEC 62734 standards. The goal is to optimize the network connectivity and develop an effective tool that can work in complex industrial sites characterized by severe obstructions. The proposed node deployment approach is validated through a case study in an oil refinery environment. It includes an ad-hoc simulation environment (RFSim tool) that implements the proposed network planning approach using 2D models of the plant, providing connectivity information based on user-defined deployment configurations. Simulation results obtained using the proposed simulation environment were validated by on-site measurements.

WiMAX Cell Level Simulation Platform Based on ns-2 and DSP Integration

WiMAX Cell Level Simulation Platform Based on ns-2 and DSP IntegrationThe WiMAX (Worldwide Interoperability for Microwave Access) system based on the IEEE 802.16 family of standards is a promising technology for last-mile access. Both IEEE 802.16 and 3GPP-LTE systems candidate for becoming the 4G network of choice. The need to evaluate multiple performance enhancing techniques like MIMO, OFDM(A), novel channel coding schemes like non-binary LDPC codes, together with development of standards like IEEE 802.21, that aims at enabling handover and interoperability between heterogeneous network types, make rapid prototyping-based simulations an important issue. This paper presents a novel approach to 4G-oriented simulation environment that integrates popular network simulator (ns-2) and a Digital Signal Processing (DSP) to enable comprehensive link layer and cell level simulations. Proposed simulation environment is intended as an evaluation platform for assessing QoS/QoE and Connection Admission Control (CAC) algorithms designed for WiMAX systems. Moreover we study ways to improve simulation time (with focus on AWGN channel simulation) by using CUDA parallel processing technology for NVIDIA graphic cards.

A modeling tool for simulating and design of on-chip network systems

The conception of Network-on-Chip (NoC) presents system designers with a new approach to the design of on-chip inter-connection structures. However, such networks present designers with a large number of design parameters and decisions, many of which are critical to the efficient operation of over-all on-chip system. To aid the design process of complex systems-on-chip, this paper presents a NoC simulation environment that has been developed and implemented using the SystemC transaction-level modeling language. The simulation environment consists of on-chip components as well as traffic generators, which can generate various types of traffic patterns. The simulation environment has also been integrated with the NoC topology generation tool being developed in our group. A set of simulation results demonstrates the types of parameters that can affect the performance of on-chip systems, including topology variations, network latency and achievable throughput. These results also verify the modeling capabilities of the proposed simulation environment.

A review of 0.18-/spl mu/m full adder performances for tree structured arithmetic circuits

The general objective of our work is to investigate the area and power-delay performances of low-voltage full adder cells in different CMOS logic styles for the predominating tree structured arithmetic circuits. A new hybrid style full adder circuit is also presented. The sum and carry generation circuits of the proposed full adder are designed with hybrid logic styles. To operate at ultra-low supply voltage, the pass logic circuit that cogenerates the intermediate XOR and XNOR outputs has been improved to overcome the switching delay problem. As full adders are frequently employed in a tree structured configuration for high-performance arithmetic circuits, a cascaded simulation structure is introduced to evaluate the full adders in a realistic application environment. A systematic and elegant procedure to scale the transistor for minimal power-delay product is proposed. The circuits being studied are optimized for energy efficiency at 0.18-/spl mu/m CMOS process technology. With the proposed simulation environment, it is shown that some survival cells in stand alone operation at low voltage may fail when cascaded in a larger circuit, either due to the lack of drivability or unsatisfactory speed of operation. The proposed hybrid full adder exhibits not only the full swing logic and balanced outputs but also strong output drivability. The increase in the transistor count of its complementary CMOS output stage is compensated by its area efficient layout. Therefore, it remains one of the best contenders for designing large tree structured arithmetic circuits with reduced energy consumption while keeping the increase in area to a minimum.

Behavioral modeling of switched-capacitor sigma-delta modulators

This paper presents a complete set of blocks implemented in the popular MATLAB SIMULINK environment, which allows designers to perform time-domain behavioral simulations of switched-capacitor (SC) sigma-delta (/spl Sigma//spl Delta/) modulators. The proposed set of blocks takes into account most of the SC /spl Sigma//spl Delta/ modulator nonidealities, such as sampling jitter, kT/C noise, and operational amplifier parameters (white noise, finite DC gain, finite bandwidth, slew rate and saturation voltages). For each block, a description of the considered effect as well as all of the implementative details are provided. The proposed simulation environment is validated by comparing the simulated behavior with the experimental results obtained from two actual circuits, namely a second-order low-pass and a sixth-order bandpass SC /spl Sigma//spl Delta/ modulator.