The emergence of vehicular edge computing (VEC) has introduced a new computational paradigm for high-quality processing of computing services in Internet of Vehicles (IoV) scenarios. However, due to the limited computational resources of the VEC server, it is not sufficient to adequately meet the demand for highly concurrent computational services in high-density vehicular communication networks. To address this issue, we consider an idle mobile vehicles assisted vehicular edge computing framework and propose a hybrid Stackelberg-Match cooperative task offloading and resource pricing algorithm (SMOP). The algorithm considers the mobility of vehicles and the duration of channels, coordinating the computational resources of fixed VEC servers and idle mobile vehicles within the vehicular network (VN). This enhances offloading efficiency and maximizes participant benefits. Specifically, the Stackelberg game is used to derive differentiated pricing schemes for idle mobile vehicles and VEC servers for different vehicular tasks, and the stable matching method is employed to determine task offloading strategies. Finally, we conduct experiments on a real Chengdu traffic dataset. The results demonstrate that the proposed solution effectively reduces offloading costs and exhibits strong robustness in handling latency-sensitive and data-intensive service requests.
{"title":"Incentive-driven computation offloading and resource pricing strategy in vehicular edge computing assisted with idle mobile vehicles","authors":"Shanchen Pang, Baoyun Chen, Xiao He, Nuanlai Wang, Zhi Lu, Shengzhe Zhao, Zixuan Fan, Yanxiang Zhang","doi":"10.1016/j.simpat.2024.103035","DOIUrl":"10.1016/j.simpat.2024.103035","url":null,"abstract":"<div><div>The emergence of vehicular edge computing (VEC) has introduced a new computational paradigm for high-quality processing of computing services in Internet of Vehicles (IoV) scenarios. However, due to the limited computational resources of the VEC server, it is not sufficient to adequately meet the demand for highly concurrent computational services in high-density vehicular communication networks. To address this issue, we consider an idle mobile vehicles assisted vehicular edge computing framework and propose a hybrid Stackelberg-Match cooperative task offloading and resource pricing algorithm (SMOP). The algorithm considers the mobility of vehicles and the duration of channels, coordinating the computational resources of fixed VEC servers and idle mobile vehicles within the vehicular network (VN). This enhances offloading efficiency and maximizes participant benefits. Specifically, the Stackelberg game is used to derive differentiated pricing schemes for idle mobile vehicles and VEC servers for different vehicular tasks, and the stable matching method is employed to determine task offloading strategies. Finally, we conduct experiments on a real Chengdu traffic dataset. The results demonstrate that the proposed solution effectively reduces offloading costs and exhibits strong robustness in handling latency-sensitive and data-intensive service requests.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"138 ","pages":"Article 103035"},"PeriodicalIF":3.5,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-13DOI: 10.1016/j.simpat.2024.103039
Jingyao Wang , Kezhong Liu , Zhitao Yuan , Xing Yang , Xiaolie Wu
With the expansion of coastal ports, the number of super-large berths is on the rise. It has become imperative to accurately assess the operational impact of these berths, optimize berth utilization, and minimize ship delays. In this study, a detailed simulation model of super-large ship arrivals and departures was developed, focusing on the Ningbo-Zhoushan Port. The model accounts for various special navigation constraints, including berthing and departure time windows, safety separations, tidal constraints, and interference from neighboring berths. The simulation results highlight a significant disparity in waiting times between arriving and departing ships, with daytime restrictions and berth time windows emerging as the primary factors influencing wait times. Consequently, several improvement measures are proposed. These include implementing priority rules based on time windows, establishing additional inner anchorages, and reducing safety separations. Among these, reducing safety separations offers the best cost-effectiveness due to its low application cost and effective results. Although these measures may lead to varying waiting times among berths, they collectively contribute to a substantial 25.6% reduction in overall waiting time. This study offers valuable insights and practical guidance for the planning, construction, and operation of super-large berths in coastal ports.
{"title":"Simulation modeling of super-large ships traffic: Insights from Ningbo-Zhoushan Port for coastal port management","authors":"Jingyao Wang , Kezhong Liu , Zhitao Yuan , Xing Yang , Xiaolie Wu","doi":"10.1016/j.simpat.2024.103039","DOIUrl":"10.1016/j.simpat.2024.103039","url":null,"abstract":"<div><div>With the expansion of coastal ports, the number of super-large berths is on the rise. It has become imperative to accurately assess the operational impact of these berths, optimize berth utilization, and minimize ship delays. In this study, a detailed simulation model of super-large ship arrivals and departures was developed, focusing on the Ningbo-Zhoushan Port. The model accounts for various special navigation constraints, including berthing and departure time windows, safety separations, tidal constraints, and interference from neighboring berths. The simulation results highlight a significant disparity in waiting times between arriving and departing ships, with daytime restrictions and berth time windows emerging as the primary factors influencing wait times. Consequently, several improvement measures are proposed. These include implementing priority rules based on time windows, establishing additional inner anchorages, and reducing safety separations. Among these, reducing safety separations offers the best cost-effectiveness due to its low application cost and effective results. Although these measures may lead to varying waiting times among berths, they collectively contribute to a substantial 25.6% reduction in overall waiting time. This study offers valuable insights and practical guidance for the planning, construction, and operation of super-large berths in coastal ports.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"138 ","pages":"Article 103039"},"PeriodicalIF":3.5,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1016/j.simpat.2024.103030
Miguel Torres-Torriti, Matias Rojas-Sepulveda
Visual diagrammatic programming and block diagrams have been indispensable tools for systems modeling and simulation across research, development, and educational fields for several decades. Despite the availability of mature commercial and free software tools, there is a lack of information publicly accessible on algorithms for processing block diagrams that represent dynamical systems and simulate the corresponding models. A gap in the existing literature is the absence of mathematically formal and complete proposals of algorithms for processing block diagrams that are multigraphs containing directed cyclic graphs, and not just simpler directed graphs. The lack of a detailed exposition concerning the practical implementation of such algorithms is also a gap. This gap is likely because the simulation systems based on block diagram descriptions that have become de facto industry standards use proprietary solutions, even if their origins can be traced back to work done in research centers and universities more than seven decades ago. In response to these challenges, this paper summarizes the historical evolution of related paradigms, such as data flow diagrams, signal flow graphs, bond graphs, and block diagrams. We propose a general algorithm for block diagram processing and present an open-source software tool for Python that implements a diagrammatic visual programming interface and the proposed block diagram processing algorithm. The key contributions to the field of systems modeling and simulation can be summarized as follows. Firstly, the exposition of the algorithm formally proving its correctness, offers transparency which facilitates further research and development in the field, enabling academics and professionals to adapt, enhance, or expand upon the existing capabilities of the tool. Secondly, the implementation of a Python library and tool released as an open-source solution for simulating signal processing and dynamical systems through block diagrams by integrating the proposed algorithm capable of efficiently handling multigraph representations, including those with directed cyclic graphs. Ensuring accessibility of the tool to researchers, developers, and educators fosters innovation, research and empowers educators by providing them with a versatile tool that can be used to teach complex systems modeling and simulation concepts in a practical, hands-on manner across various domains, such as control systems, electrical engineering, and computer science.
{"title":"An algorithm for processing block diagram models of dynamical systems and an open-source visual-programming simulation tool","authors":"Miguel Torres-Torriti, Matias Rojas-Sepulveda","doi":"10.1016/j.simpat.2024.103030","DOIUrl":"10.1016/j.simpat.2024.103030","url":null,"abstract":"<div><div>Visual diagrammatic programming and block diagrams have been indispensable tools for systems modeling and simulation across research, development, and educational fields for several decades. Despite the availability of mature commercial and free software tools, there is a lack of information publicly accessible on algorithms for processing block diagrams that represent dynamical systems and simulate the corresponding models. A gap in the existing literature is the absence of mathematically formal and complete proposals of algorithms for processing block diagrams that are multigraphs containing directed cyclic graphs, and not just simpler directed graphs. The lack of a detailed exposition concerning the practical implementation of such algorithms is also a gap. This gap is likely because the simulation systems based on block diagram descriptions that have become <em>de facto</em> industry standards use proprietary solutions, even if their origins can be traced back to work done in research centers and universities more than seven decades ago. In response to these challenges, this paper summarizes the historical evolution of related paradigms, such as data flow diagrams, signal flow graphs, bond graphs, and block diagrams. We propose a general algorithm for block diagram processing and present an open-source software tool for Python that implements a diagrammatic visual programming interface and the proposed block diagram processing algorithm. The key contributions to the field of systems modeling and simulation can be summarized as follows. Firstly, the exposition of the algorithm formally proving its correctness, offers transparency which facilitates further research and development in the field, enabling academics and professionals to adapt, enhance, or expand upon the existing capabilities of the tool. Secondly, the implementation of a Python library and tool released as an open-source solution for simulating signal processing and dynamical systems through block diagrams by integrating the proposed algorithm capable of efficiently handling multigraph representations, including those with directed cyclic graphs. Ensuring accessibility of the tool to researchers, developers, and educators fosters innovation, research and empowers educators by providing them with a versatile tool that can be used to teach complex systems modeling and simulation concepts in a practical, hands-on manner across various domains, such as control systems, electrical engineering, and computer science.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"138 ","pages":"Article 103030"},"PeriodicalIF":3.5,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-09DOI: 10.1016/j.simpat.2024.103032
Inseong Hwang , Junghyeok Lee , Huibeom Kang, Gilhyeon Lee, Hyun Kim
In computer architecture studies, simulators are crucial for design verification, reducing research and development time and ensuring the high accuracy of verification results. Several studies have developed and employed a verification environment by designing a custom in-house simulator that verifies the performance improvement of the proposed architecture for each research purpose by integrating multiple simulators or modifying existing ones. Recent advancements in deep neural networks and increased computational complexity have prompted research into emerging technologies, such as GPUs, processing-in-memory (PIM), and neural processing units (NPUs). Recently, custom in-house simulators were developed and actively employed for performance verification. However, constructing proper custom in-house simulators requires a greater grasp of the support functions and characteristics of current architectural simulators, which constitute the backbone of simulator creation. To meet these criteria, a comprehensive comparative analysis was conducted by examining the structures and output metrics supported across various architecture simulators, including representative CPU and memory simulators. Furthermore, it analyzes actual case studies of in-house simulators developed in recent emerging technology research ( i.e., GPUs, NPUs, PIM). Additionally, we examine the characteristics of compilers that support optimization for various recent workloads and simulators by analyzing case studies in which the integration of simulators and compilers has contributed to optimizing the overall simulator operations. Analyzing the overall verification process using these simulators, comparing each component, and confirming actual cases can provide essential insights for selecting and developing simulators suitable for computer architecture research. Consequently, this study contributes to maximizing the accuracy and efficiency of computer architecture research.
在计算机体系结构研究中，模拟器对于设计验证、减少研发时间和确保验证结果的高精度至关重要。有几项研究通过设计定制的内部模拟器，开发并使用了验证环境，通过集成多个模拟器或修改现有模拟器，验证了针对每个研究目的提出的架构的性能改进。深度神经网络的最新进展和计算复杂性的增加促使人们对 GPU、内存处理（PIM）和神经处理单元（NPU）等新兴技术进行研究。最近，人们开发了定制的内部模拟器，并积极用于性能验证。然而，要构建合适的定制内部模拟器，需要进一步掌握当前架构模拟器的支持功能和特点，这些是创建模拟器的基础。为了满足这些标准，我们通过研究各种架构模拟器（包括具有代表性的 CPU 和内存模拟器）所支持的结构和输出指标，进行了全面的比较分析。此外，我们还分析了近期新兴技术研究（如 GPU、NPU、PIM）中开发的内部模拟器的实际案例研究。此外，我们还通过分析模拟器和编译器的集成有助于优化整个模拟器操作的案例研究，考察了支持针对各种最新工作负载和模拟器进行优化的编译器的特性。分析使用这些模拟器的整体验证过程、比较每个组件并确认实际案例，可为选择和开发适合计算机体系结构研究的模拟器提供重要启示。因此，本研究有助于最大限度地提高计算机体系结构研究的准确性和效率。
{"title":"Survey of CPU and memory simulators in computer architecture: A comprehensive analysis including compiler integration and emerging technology applications","authors":"Inseong Hwang , Junghyeok Lee , Huibeom Kang, Gilhyeon Lee, Hyun Kim","doi":"10.1016/j.simpat.2024.103032","DOIUrl":"10.1016/j.simpat.2024.103032","url":null,"abstract":"<div><div>In computer architecture studies, simulators are crucial for design verification, reducing research and development time and ensuring the high accuracy of verification results. Several studies have developed and employed a verification environment by designing a custom in-house simulator that verifies the performance improvement of the proposed architecture for each research purpose by integrating multiple simulators or modifying existing ones. Recent advancements in deep neural networks and increased computational complexity have prompted research into emerging technologies, such as GPUs, processing-in-memory (PIM), and neural processing units (NPUs). Recently, custom in-house simulators were developed and actively employed for performance verification. However, constructing proper custom in-house simulators requires a greater grasp of the support functions and characteristics of current architectural simulators, which constitute the backbone of simulator creation. To meet these criteria, a comprehensive comparative analysis was conducted by examining the structures and output metrics supported across various architecture simulators, including representative CPU and memory simulators. Furthermore, it analyzes actual case studies of in-house simulators developed in recent emerging technology research ( <em>i.e.</em>, GPUs, NPUs, PIM). Additionally, we examine the characteristics of compilers that support optimization for various recent workloads and simulators by analyzing case studies in which the integration of simulators and compilers has contributed to optimizing the overall simulator operations. Analyzing the overall verification process using these simulators, comparing each component, and confirming actual cases can provide essential insights for selecting and developing simulators suitable for computer architecture research. Consequently, this study contributes to maximizing the accuracy and efficiency of computer architecture research.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"138 ","pages":"Article 103032"},"PeriodicalIF":3.5,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The proliferation of cloud-based applications, data, and services has significantly transformed digital interactions, driven by the widespread use of powerful smart devices and the expansion of cloud ecosystems. These ecosystems rely on data centers composed of Physical Machines (PMs) and Virtual Machines (VMs). The increasing demand for cloud services has led to extensive use of physical servers, resulting in high energy consumption and inefficient resource utilization. Consequently, optimizing resource allocation and reducing power consumption have become pivotal challenges in data center management. A key strategy to address these challenges is Virtual Machine Consolidation (VMC), which optimizes computing resources by consolidating multiple VMs into fewer PMs. This paper comprehensively reviews the three critical phases involved in VMC: PM detection, VM selection, and VM placement. Through an extensive analysis of literature spanning from 2015 to 2024, this review seeks to provide valuable insights into the current landscape of VMC and its potential ramifications on the performance and sustainability of cloud computing. The main flaw in the articles is that the various authors focused on different assessment metrics when the emphasis should have been on the three primary steps in VMC. The importance of this categorization lies in its ability to provide clarity, organization, and a structured framework for comprehending the intricate landscape of VMC. VMC is a multifaceted undertaking encompassing numerous subtasks. Categorization simplifies this complexity by breaking it down into manageable components. Researchers can address each category individually, potentially leading to more focused and effective solutions.
{"title":"VM consolidation steps in cloud computing: A perspective review","authors":"Seyyed Meysam Rozehkhani , Farnaz Mahan , Witold Pedrycz","doi":"10.1016/j.simpat.2024.103034","DOIUrl":"10.1016/j.simpat.2024.103034","url":null,"abstract":"<div><div>The proliferation of cloud-based applications, data, and services has significantly transformed digital interactions, driven by the widespread use of powerful smart devices and the expansion of cloud ecosystems. These ecosystems rely on data centers composed of Physical Machines (PMs) and Virtual Machines (VMs). The increasing demand for cloud services has led to extensive use of physical servers, resulting in high energy consumption and inefficient resource utilization. Consequently, optimizing resource allocation and reducing power consumption have become pivotal challenges in data center management. A key strategy to address these challenges is Virtual Machine Consolidation (VMC), which optimizes computing resources by consolidating multiple VMs into fewer PMs. This paper comprehensively reviews the three critical phases involved in VMC: PM detection, VM selection, and VM placement. Through an extensive analysis of literature spanning from 2015 to 2024, this review seeks to provide valuable insights into the current landscape of VMC and its potential ramifications on the performance and sustainability of cloud computing. The main flaw in the articles is that the various authors focused on different assessment metrics when the emphasis should have been on the three primary steps in VMC. The importance of this categorization lies in its ability to provide clarity, organization, and a structured framework for comprehending the intricate landscape of VMC. VMC is a multifaceted undertaking encompassing numerous subtasks. Categorization simplifies this complexity by breaking it down into manageable components. Researchers can address each category individually, potentially leading to more focused and effective solutions.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"138 ","pages":"Article 103034"},"PeriodicalIF":3.5,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-07DOI: 10.1016/j.simpat.2024.103033
Jun Niu , Jia Wang
Well-designed spatial configurations of public transport stops and routes in big cities contribute to enhancing daily travel services for citizens, effectively mitigating traffic congestion, and addressing other pertinent challenges. When examining spatial layouts of public transport networks (PTNs), various reachability demands between stops or urban Points of Interest (POIs) are crucial issues should be firstly taken into account. Existing methods to investigate spatial reachability properties of PTNs generally need to construct some evaluation functions, or survey reachability metrics through some network analysis techniques. These methods are often impractical, as the functional relations always cannot be accurately defined, or some global network metrics cannot provide explicit evidences for PTN layout planning or optimization.
In this paper, we introduce spatial model checking techniques to the formal verification of the reachability specifications of PTN to guarantee the rationality of PTN layout. First, we extend closure space structure by incorporating attribute labeling functions and logical propositions for public transport stops and routes to develop a formal spatial verification model for PTN spatial layout. Second, we propose several novel reachability operators based on the logical operators of the Spatial Logic for Closure Space (SLCS) to facilitate the logical characterization of reachability specifications. Third, we perform the verification of the transformed reachability formulas by the spatial model checker topochecker. Examples demonstrate the effectiveness of our approach and indicate that it can perform automatic, descriptive and comprehensible verification of the reachability properties PTN layouts.
{"title":"Model checking spatial reachability specifications of public transport networks","authors":"Jun Niu , Jia Wang","doi":"10.1016/j.simpat.2024.103033","DOIUrl":"10.1016/j.simpat.2024.103033","url":null,"abstract":"<div><div>Well-designed spatial configurations of public transport stops and routes in big cities contribute to enhancing daily travel services for citizens, effectively mitigating traffic congestion, and addressing other pertinent challenges. When examining spatial layouts of public transport networks (PTNs), various reachability demands between stops or urban Points of Interest (POIs) are crucial issues should be firstly taken into account. Existing methods to investigate spatial reachability properties of PTNs generally need to construct some evaluation functions, or survey reachability metrics through some network analysis techniques. These methods are often impractical, as the functional relations always cannot be accurately defined, or some global network metrics cannot provide explicit evidences for PTN layout planning or optimization.</div><div>In this paper, we introduce spatial model checking techniques to the formal verification of the reachability specifications of PTN to guarantee the rationality of PTN layout. First, we extend closure space structure by incorporating attribute labeling functions and logical propositions for public transport stops and routes to develop a formal spatial verification model for PTN spatial layout. Second, we propose several novel reachability operators based on the logical operators of the Spatial Logic for Closure Space (SLCS) to facilitate the logical characterization of reachability specifications. Third, we perform the verification of the transformed reachability formulas by the spatial model checker topochecker. Examples demonstrate the effectiveness of our approach and indicate that it can perform automatic, descriptive and comprehensible verification of the reachability properties PTN layouts.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"138 ","pages":"Article 103033"},"PeriodicalIF":3.5,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-06DOI: 10.1016/j.simpat.2024.103031
Min Wang , Ziyi Gao , Haoyuan Wang , Sibo Qiao , Jinhai Wang
The diverse service requests in industrial Internet networks require flexible and efficient service chain deployment to ensure the quality of service (QoS). However, current deployment algorithms for service chains are primarily designed to guarantee only low end-to-end latency; they often overlook the amount of service chains that can be accommodated by the network and could lead to severe network load imbalances, significantly reducing service efficiency and causing serious network congestion issues. To address the above issues, we develop a mathematical model of the network topology and service request chains by integrating Network Function Virtualization (NFV) and Software Defined Networking (SDN). Utilizing network calculus theory, we derive the upper bound of end-to-end delay for service chain routing and analyzed the relationship between the upper bound of service chain routing delay and the resource allocation of Virtual Network Function (VNF) nodes. Based on the aforementioned model, we propose a novel service chain deployment algorithm named the Delay-Aware Load-Balanced Routing Algorithm (DLBRA). DLBRA comprehensively considers network traffic load balancing and end-to-end latency of service chains, rationally allocating VNF node resources to complete the determined service chain routing deployment. Experimental results indicate that, compared to the shortest path and load balancing algorithms, DLBRA not only ensures that the end-to-end delay of the service chain meets its QoS requirements, but also effectively reduces network load imbalance, significantly increasing the number of service chain requests that the network can accommodate. Additionally, DLBRA provides tailored deployment guidance for different types of service chains, such as latency-sensitive and data-intensive service chains, ensuring optimal utilization of network resources. This algorithm enhances the efficiency of service chain deployment in industrial internet scenarios and possesses broad application potential in other network environments where delay optimization and load balancing are critical, such as intelligent transportation, cloud computing, and 5G networks.
{"title":"End-to-end latency upper bounds and service chain deployment algorithm based on industrial internet network","authors":"Min Wang , Ziyi Gao , Haoyuan Wang , Sibo Qiao , Jinhai Wang","doi":"10.1016/j.simpat.2024.103031","DOIUrl":"10.1016/j.simpat.2024.103031","url":null,"abstract":"<div><div>The diverse service requests in industrial Internet networks require flexible and efficient service chain deployment to ensure the quality of service (QoS). However, current deployment algorithms for service chains are primarily designed to guarantee only low end-to-end latency; they often overlook the amount of service chains that can be accommodated by the network and could lead to severe network load imbalances, significantly reducing service efficiency and causing serious network congestion issues. To address the above issues, we develop a mathematical model of the network topology and service request chains by integrating Network Function Virtualization (NFV) and Software Defined Networking (SDN). Utilizing network calculus theory, we derive the upper bound of end-to-end delay for service chain routing and analyzed the relationship between the upper bound of service chain routing delay and the resource allocation of Virtual Network Function (VNF) nodes. Based on the aforementioned model, we propose a novel service chain deployment algorithm named the Delay-Aware Load-Balanced Routing Algorithm (DLBRA). DLBRA comprehensively considers network traffic load balancing and end-to-end latency of service chains, rationally allocating VNF node resources to complete the determined service chain routing deployment. Experimental results indicate that, compared to the shortest path and load balancing algorithms, DLBRA not only ensures that the end-to-end delay of the service chain meets its QoS requirements, but also effectively reduces network load imbalance, significantly increasing the number of service chain requests that the network can accommodate. Additionally, DLBRA provides tailored deployment guidance for different types of service chains, such as latency-sensitive and data-intensive service chains, ensuring optimal utilization of network resources. This algorithm enhances the efficiency of service chain deployment in industrial internet scenarios and possesses broad application potential in other network environments where delay optimization and load balancing are critical, such as intelligent transportation, cloud computing, and 5G networks.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"138 ","pages":"Article 103031"},"PeriodicalIF":3.5,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A dynamic microscopic traffic flow simulation within a ring arterial context was developed to investigate the effects of access point spacing on urban arterial flow under a right-in-right-out access management system. The microscopic traffic flow model, centered on car-following and lane-changing behaviors, was established based on vehicle interactions. The car-following aspect encompasses free driving, car-following behavior, and deceleration and braking states while lane-changing considerations include decision-making and acceptable gap assessment. Experimental scenarios account for arterial traffic density, access traffic demand intensity, average access point spacing, and variation coefficient of access point spacing. The traffic flow and speeds within the ring arterial were evaluated across 5040 operational conditions (equating to 5880 simulation hours). The traffic flow trends and speed variations with density across different access spacing scenarios were analyzed. We made an intriguing discovery: the impact on arterial traffic flow increases with larger average access point spacing, challenging conventional traffic planning recommendations that advocate for greater spacing. Additionally, access traffic minimally affects the overall arterial flow when arterial traffic volume is low. By highlighting these critical insights, this study introduces novel considerations for designing and managing access points.
{"title":"Do the sparser access points have less impact on arterial traffic? A microscopic simulation-based study","authors":"Jing Zhao , Yulan Xia , Chaojun Wang , Jairus Odawa","doi":"10.1016/j.simpat.2024.103036","DOIUrl":"10.1016/j.simpat.2024.103036","url":null,"abstract":"<div><div>A dynamic microscopic traffic flow simulation within a ring arterial context was developed to investigate the effects of access point spacing on urban arterial flow under a right-in-right-out access management system. The microscopic traffic flow model, centered on car-following and lane-changing behaviors, was established based on vehicle interactions. The car-following aspect encompasses free driving, car-following behavior, and deceleration and braking states while lane-changing considerations include decision-making and acceptable gap assessment. Experimental scenarios account for arterial traffic density, access traffic demand intensity, average access point spacing, and variation coefficient of access point spacing. The traffic flow and speeds within the ring arterial were evaluated across 5040 operational conditions (equating to 5880 simulation hours). The traffic flow trends and speed variations with density across different access spacing scenarios were analyzed. We made an intriguing discovery: the impact on arterial traffic flow increases with larger average access point spacing, challenging conventional traffic planning recommendations that advocate for greater spacing. Additionally, access traffic minimally affects the overall arterial flow when arterial traffic volume is low. By highlighting these critical insights, this study introduces novel considerations for designing and managing access points.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"138 ","pages":"Article 103036"},"PeriodicalIF":3.5,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-01DOI: 10.1016/j.simpat.2024.103028
Francisco Jiménez-Morales , José-Luis Guisado-Lizar , José Manuel Guerra
The Q-switching (QS) phenomenon in lasers refers to the production of high intensity pulses by means of a saturable absorber (passive method) or by modifying the reflectivity or losses of the intracavity optics or mirrors (active method). Theoretically, the QS is studied through the laser rate equations which are useful to predict, at least qualitatively and roughly, the fundamental aspects of laser dynamics. However, specific details such as the spatial distribution of the intensity of the laser emission escape the simplicity of the rate equations. In this work we present a two dimensional cellular automata model (CA) to study the QS phenomenology for both the passive and the active method. To simulate the passive method we consider a spatial distribution of cells whose physical properties emulate those of the saturable adsorbers. And for the active method we introduce a periodic modulation of the lifetime of the photons inside the cavity. We have done numerous numerical simulations that show that despite the simplicity of the evolution rules, the AC model is capable of obtaining the main dynamics of operation of the laser by modifying the system parameters such as the pumping probability and the properties of the absorber.
{"title":"A cellular automata model of a laser reproducing laser passive and active Q-Switching","authors":"Francisco Jiménez-Morales , José-Luis Guisado-Lizar , José Manuel Guerra","doi":"10.1016/j.simpat.2024.103028","DOIUrl":"10.1016/j.simpat.2024.103028","url":null,"abstract":"<div><div>The Q-switching (QS) phenomenon in lasers refers to the production of high intensity pulses by means of a saturable absorber (passive method) or by modifying the reflectivity or losses of the intracavity optics or mirrors (active method). Theoretically, the QS is studied through the laser rate equations which are useful to predict, at least qualitatively and roughly, the fundamental aspects of laser dynamics. However, specific details such as the spatial distribution of the intensity of the laser emission escape the simplicity of the rate equations. In this work we present a two dimensional cellular automata model (CA) to study the QS phenomenology for both the passive and the active method. To simulate the passive method we consider a spatial distribution of cells whose physical properties emulate those of the saturable adsorbers. And for the active method we introduce a periodic modulation of the lifetime of the photons inside the cavity. We have done numerous numerical simulations that show that despite the simplicity of the evolution rules, the AC model is capable of obtaining the main dynamics of operation of the laser by modifying the system parameters such as the pumping probability and the properties of the absorber.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"138 ","pages":"Article 103028"},"PeriodicalIF":3.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-24DOI: 10.1016/j.simpat.2024.103027
Clement Daah, Amna Qureshi, Irfan Awan, Savas Konur
The financial sector is increasingly facing advanced cyber threats, necessitating a shift from traditional security measures to more dynamic frameworks. This study presents a novel integration of Zero Trust architecture with hybrid access control system and blockchain technology to enhance security in financial institutions. Zero Trust enforces continuous authentication and dynamic access controls, while blockchain secures digital identities and transaction logs through its immutable ledger, ensuring data integrity and non-repudiation. The proposed framework, evaluated using OMNeT++ simulations enhanced by Ethereum-Ganache, shows improved detection accuracy, reduced false positives, and increased resistance to insider threats and other attacks. It also strengthens compliance with regulatory requirements through robust audit trails, providing enhanced protection for sensitive financial data.
{"title":"Simulation-based evaluation of advanced threat detection and response in financial industry networks using zero trust and blockchain technology","authors":"Clement Daah, Amna Qureshi, Irfan Awan, Savas Konur","doi":"10.1016/j.simpat.2024.103027","DOIUrl":"10.1016/j.simpat.2024.103027","url":null,"abstract":"<div><div>The financial sector is increasingly facing advanced cyber threats, necessitating a shift from traditional security measures to more dynamic frameworks. This study presents a novel integration of Zero Trust architecture with hybrid access control system and blockchain technology to enhance security in financial institutions. Zero Trust enforces continuous authentication and dynamic access controls, while blockchain secures digital identities and transaction logs through its immutable ledger, ensuring data integrity and non-repudiation. The proposed framework, evaluated using OMNeT++ simulations enhanced by Ethereum-Ganache, shows improved detection accuracy, reduced false positives, and increased resistance to insider threats and other attacks. It also strengthens compliance with regulatory requirements through robust audit trails, providing enhanced protection for sensitive financial data.</div></div>","PeriodicalId":49518,"journal":{"name":"Simulation Modelling Practice and Theory","volume":"138 ","pages":"Article 103027"},"PeriodicalIF":3.5,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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