Efficient Resource Utilization in Parallel and Distributed Systems

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Sun, J., 2020. Fault tolerance mechanism of distributed system for marine communication network. In: Gong, D.; Zhang, M., and Liu, R. (eds.), Advances in Coastal Research: Engineering, Industry, Economy, and Sustainable Development. Journal of Coastal Research, Special Issue No. 106, pp. 605–608. Coconut Creek (Florida), ISSN 0749-0208.When the communication network fails or the signal is interrupted, the distributed fault-tolerant system can continue to complete the communication task, which is needed to improve the fault-tolerant performance of the distributed system. Therefore, the key technologies of fault tolerance need to be studied, including the distributed fault-tolerant communication network simulation platform, the communication-network information-storage data structure, the communication protocol between communication network nodes, and the fault-tolerant algorithm of distributed communication network system. In the marine environment, the fleet exchanges data through wireless networks to understand the situation of the fleet-detection area, which can share the processing and calculation tasks. However, the marine environment is complex and changeable, which can cause great interference to the wireless signal, such as sea and cloud-rain clutter. These marine environments will cause the network communication signals to be greatly disturbed, which makes the distributed system unable to guarantee the communication interconnection between each node at any time. Therefore, a data-sharing and distributed-system platform needs to be built, which will design a reasonable system fault-tolerance mechanism. Through the fault-tolerance mechanism of the communication network system, the problem of frequent-node exits can be solved. By optimizing the fault-tolerant strategy of distributed architecture, the system's disaster resistance can be improved. In this research, a fault-tolerance mechanism for a distributed system was designed, which is more suitable for node election.

Some empirical results concerning the modelling of industrial distribution systems : Atkins DR (1972) PhD. thesis, University Library, School of Industrial and Business Studies, Warwick University, Coventry CV4 7AL, England

A large-scale distributed system may experience software or hardware failures that lead to undesirable down-time of the system. While the failure of a hardware node is common for large distributed systems, the reliability of software can also be a significant factor. System reliability can be improved by integrating both hardware and software based reliability techniques. We presented a combined fault-tolerant approach to improve reliability for a large monitoring system through failure detection, isolation, and recovery. The proposed approach was applied to real-time distributed monitoring system and preliminary experiments showed substantial improvement on reliability. Experiments also showed that our approach is scaleable to meet the needs of large-scale monitoring systems.

In Japan, in order to reduce greenhouse gas emissions, Photovoltaic generation (PV) is being focused on recently. According to Japanese governmental policy, a large amount of PVs will be introduced into the distribution system in the near future. However, the output of PV depends on weather conditions and climate may change rapidly or randomly. As a result, voltage in distribution system with many PVs will fluctuate; nevertheless, distribution network operator must keep voltage in network within adequate range determined by law. By contrast, Step Voltage Regulator (SVR), which is located on distribution line to control voltage, has time delay to operate against voltage change. Hence, SVR could cause voltage deviation from adequate range when a large amount of PVs are connected to network. From this point of view, several novel equipment that control voltage flexibility such as Static Var compensator (SVC) and Battery are being noted lately. Although, this kind of device using power electronics technology is usually expensive, and huge cost is necessary to introduce these devices into many distribution systems in which there are lots of PVs. For this reason, it is necessary to control voltage with established device such as LRT (Load Ratio control Transformer) and SVR over the next 10 or 20 years, but these devices have several issues such as voltage deviation in case that there are a lot of PVs. The authors focused on SVR and analyzed the cause of voltage deviation by SVR. By analyzing several cases, the authors found the causes of voltage deviation and effective control method of SVR. In proposed method, it can realize to both reduce the cost and keep voltage within adequate range even if there are a lot of PVs in the distribution system.

The paper provides the design of a distributed test system for testing distributed GUI (Graphical User Interface) applications. The distributed GUI application that is considered allows multiple operators or users to interact with a distributed system in parallel. The distributed GUI application allows the use of existing GUI test frameworks for local test execution and offers additional services of coordination and synchronization among the deployed GUI test frameworks, test verdict arbitration, and debugging support, all of which are needed to deal with the concurrent nature of the system under test. In addition, the paper offers a test specification method for test cases that is based on the semantic model of a concurrent event flow graph. This method allows the automatic test case execution on top of the suggested distributed test system. The overall approach allows the extension of testing of single GUI application systems towards testing of distributed GUI application systems by preserving investments in test automation for single GUI testing.

Vehicular networking is an innovation with a variety of applications such as road safety, traffic efficiency, and autonomous driving. It encompasses vehicle-to-vehicle and vehicle-to-infrastructure communication to support cooperative communication. However, there are many challenges to secure exchanged messages. Currently, secure data communication in vehicular networks is mostly carried out by central security supporting elements, i.e Public Key Infrastructure (PKI). Due to increasing numbers of vehicles, connected and autonomous cars, the corresponding environmental concerns, and the evolved mobility forms, PKI-based security will not be sufficient for the security of the future vehicular ecosystem. Therefore, a new vehicle identity scheme and a novel distributed and autonomous model for recognizing authorized and non-authorized vehicles are needed. Biological systems can provide examples of how evolution has solved similar problems of identifying actors in distributed systems. In ant colonies, for example, nestmate recognition is a distributed and cooperative colony-wide process. Based on the principles at work in an ant colony, we propose a novel, distributed and dynamic, collective and cooperative, intelligence-based recognition of identity in vehicular networks. We will develop detailed analogies between ant colonies and vehicular networks, model the identity recognition processes of social insects, and simplify and tune these models for use in vehicle networks. This will enable a resilient, efficient and secure distributed communication system based on Cyberphysical Identification Component (CIC) profiles.

The integrated optimization of charging station (CS) placement and distributed generation (DG) placement in distribution networks has been examined in this work. The aim is to improve system performance while incorporating the effects of load models and traffic congestion. Power distribution systems have become more complex due to the widespread adoption of electric vehicles (EVs) and the increasing penetration of DGs. To ensure power system stability, efficient resource utilization is essential. This paper proposes an integrated optimization model that combines DG allocation and CS placement using a Quokka Swarm Optimization (QSO) considering both traffic congestion and dynamic load profiles for realistic modelling. The proposed approach aims to minimize system losses, enhance voltage stability and mitigate the impact of traffic congestion on system performance. Simulations are performed with modified IEEE 69-bus radial distribution system. Proposed method for DG allocation and CS placement using QSO is compared with Grey Wolf Optimization (GWO) for analysis. The results show that optimal integration of DGs and CSs leads to a 48.23% reduction in active power losses (from 224.85 kW to 116.41 kW) and an improvement in the minimum bus voltage from 0.9101 p.u. to 0.9568 p.u. (over 5.15%,) under peak load and high congestion scenarios. These findings confirm that strategic coordination of DG and CS locations significantly enhances grid performance.

Checkpointing and rollback recovery is a very effective technique to tolerate faults, provided the application is able to recover from a previous checkpoint and proceed with a failure-free computation. However, this technique may fall short if the checkpoint files are somehow contaminated by errors. This paper presents two mechanisms that may be used to determine if a committed checkpoint is error-free or not. These techniques can be used simultaneously for error detection and failure recovery. Both of them are based on checkpoint duplication: one makes use of spatial redundancy while the other is based on temporal redundancy. We discuss the main problems and trade-offs that have to be dealt with to implement these techniques. We then present a performance study that clearly shows the pros and cons of each one. As far as we know, this paper presents the first implementation of these mechanisms in a standard parallel computing system.

Modern day computer architectures offer ever-increasing support for parallel processing, still it turns out to be quite difficult for programmers and therefore programs to tap into these parallel resources. To benefit from real general-purpose parallel computing we claim that it is likely that a paradigm shift is needed in the way we think about programming. This change of thought in turn will need to be reflected in future programming languages as well. We think that the field of process algebra provides thorough insight in how to reason about the construction of software for concurrent systems and will be one of the enabling technologies supporting this transition. The wish to connect process algebra, a mathematical theory, to the world of computer-readable and executable specifications led to the development of PSF (Process Specification Formalism). PSF is an implementation of the process algebra ACP (Algebra of Communicating Processes) integrating ASF (Algebraic Specification Formalism) to specify algebraic data types. One of the first publications on PSF appeared in Fundamenta Informaticae in 1990. Here we stated as the first sentence of the abstract: "Traditional methods for programming sequential machines are inadequate for specifying parallel systems". Unfortunately, though some advancements have been made since 1990, we can still uphold this statement 20 years later. This current report documents the developments that lead to the construction of PSF and the 1990 publication and moreover it also documents how PSF and its tools have evolved since 1990 taking the conclusion and the outlook for future work from the original article as a reference point. Using the knowledge gained both in constructing tools for PSF and in using PSF to specify concurrent systems, we will judge, discuss and criticise the design decisions taken and show paths for future developments.

Chen, Y.; Li, Z.; Li, P.; Gao, H.; Jin, T.; Du, P., and Zhang, Y., 2020. Evaluation of water resources utilization effectiveness based on eco-economics theory. In: Bai, X. and Zhou, H. (eds.), Advances in Water Resources, Environmental Protection, and Sustainable Development. Journal of Coastal Research, Special Issue No. 115, pp. 148-150. Coconut Creek (Florida), ISSN 0749-0208.Facing the increasingly severe water resources situation, how to manage water resources reasonably and effectively, and improve the utilization efficiency and efficiency of water resources is an inevitable requirement for the overall development of China's economic and social water resources ecological environment system. Based on this, the effect of water resources utilization is evaluated based on the theory of ecological economics. The SVM correlation model algorithm is proposed. The dynamic analysis and simulation evaluation are carried out through SD simulation technology, and the total system flow diagram of regional water resources utilization evaluation is established. Based on the maximum flow algorithm, the incentive degree of water resources ecological compensation mechanism is studied. InVEST model and household survey are used to calculate the new water conservation and land use conversion costs. After considering the risk of water resources ecosystem loss, the welfare cost method is adopted. On the county scale, the potential objects of ecological compensation for water resources in the Weihe River Basin are identified. The results show that there are obvious spatial differences in water resources ecological compensation efficiency coefficients in Gansu section of Weihe River Basin. Weiyuan County with the highest runoff is 1.26, Gangu County with the lowest runoff is 0.46. The efficiency of the project can be increased by 40.54% after spatial screening of regional compensation objects. Through the evaluation of water resources utilization and water resources policy simulation, it provides a reference for the coordinated development of water resources and social economy in China.

PAPA: A parallel programming assistant powered by IBM Watson cognitive computing technology

The adoption of the Ship Inspection Report Programme (SIRE) by PT Pertamina International Shipping demonstrates the company's commitment to enhancing maritime safety and adhering to international standards set by the OCIMF. In practice, however, its implementation encounters several obstacles, including limited assimilation of program objectives, insufficient resources, and less-than-optimal internal communication and safety culture. This research evaluates the effectiveness of SIRE implementation across five dimensions of organizational effectiveness: clarity of goals, efficiency in resource utilization, organizational characteristics, internal communication, and adaptability to change. A descriptive qualitative method was applied, using purposive sampling to select five key informants directly involved in the program, with data gathered through in-depth interviews and analyzed thematically. The results indicate that although SIRE has been implemented effectively overall, significant challenges remain, particularly the lack of comprehensive understanding of its core purpose, as it is often viewed only as a vetting preparation tool. Other issues include the limited number of internal inspectors, weak inter-unit coordination and communication, and the absence of an adaptive roadmap to anticipate regulatory developments and external risks. To ensure sustained effectiveness, this study suggests enhancing case-based training, digitizing the inspection system, forming cross-functional teams, and formulating risk-based adaptive strategies.

Microservices architecture has emerged as a transformative paradigm in modern software development, enabling organizations to build resilient and scalable distributed systems. This comprehensive exploration delves into the fundamental principles, implementation strategies, and real-world applications of microservices architecture. The architectural framework facilitates independent service deployment, enhanced fault isolation, and streamlined maintenance processes while promoting technology stack flexibility. Through the implementation of sophisticated monitoring patterns, testing strategies, and data consistency mechanisms, organizations can effectively address common challenges in distributed systems. The integration of enterprise architecture principles with microservices has demonstrated significant improvements in resource utilization, system reliability, and operational efficiency. The adoption of API gateway patterns, security frameworks, and containerization technologies further enhances system performance and scalability. Real-world applications, particularly in e-commerce platforms, showcase the practical benefits of microservices architecture in managing complex business operations while maintaining high availability and performance standards.