Port Network Research Articles

EXPERIENCES AND CHALLENGES OF INTELLIGENT REMOTE CONTROL BREAKER (IRCB) DEVELOPMENT

The growing adoption of digital technologies in power distribution networks has highlighted limitations in traditional substation circuit breaker (CB) control methods, particularly their dependence on dedicated hardware and complex installations. This study addresses these challenges by proposing an alternative solution for Remote Circuit Breaker (RCB) control using mobile devices. The primary objective is to simplify and enhance the operational flexibility of circuit breaker control without requiring extensive infrastructure modifications. The proposed method utilizes mobile devices equipped with a Human-Machine Interface (HMI) that connect directly to network ports located outside power distribution substation buildings. This approach minimizes the need for additional hardware installations and reduces operational complexity. Preliminary findings demonstrate that this solution provides reliable control capabilities while maintaining ease of deployment and cost-effectiveness. The results suggest that adopting mobile-device-based RCB control can significantly streamline substation operations and contribute to the modernization of power distribution systems.

Performance Evaluation of Microtik Routers According to Electromagnetic Compatibility Testing Standards

This study presents a detailed analysis of the performance of the MikroTik router, model RB912UAG-2HPnD, according to European and international electromagnetic compatibility test standards. Tests included measurements of conducted and radiated emissions, harmonic current emissions, flicker and voltage fluctuations, as well as evaluation of equipment immunity to radiated electromagnetic fields, conductive induced radio disturbances, electrostatic discharges and rapid voltage pulse trains in accordance with the product standard SM EN 301 489-1, the emission requirements standard SM EN 55032, and the standard series for immunity tests SM EN IEC 61000. The test results showed that the router complies with all necessary requirements, with significant passing margins above the established limits. For example, the conducted emissions from the power and network ports had minimum pass margins of -14.33 dB to 23.128 MHz and -9.29 dB to 23.128 MHz, respectively. Radiated emissions below 1 GHz and above 1 GHz demonstrated compliance without exceeding the established pass margins. Electrostatic discharge tests and exposure to radio frequency electromagnetic fields confirmed that the router meets the specified performance criteria, ensuring proper operation under electromagnetic interference conditions. Measurements of harmonic current and voltage and flicker fluctuations indicated the router's compliance with applicable standards, demonstrating a power consumption below 75 W and a level of voltage fluctuations that does not affect equipment performance. During and after the immunity tests, the router performed as intended with no loss of functionality or critical stored data. These results emphasize the reliability and stability of the MikroTik router, highlighting the importance of compliance with strict electromagnetic compatibility standards for use in critical environments. The evaluation provides a solid basis for adapting the router to applications that require strict electromagnetic standards, ensuring robust and reliable performance.

Network algebraization and port relationship for power‐electronic‐dominated power systems

AbstractIn the classical differential‐algebraic equations (DAEs) framework for the traditional power system stability analysis, synchronous generators are depicted by differential equations and network by algebraic equations under the quasi‐steady‐state assumption. Differently, in the power‐electronic‐dominated power system (PEDPS), the dynamics of transmission lines of network for fully differential equations should be considered, due to the rapid response of converters' controls, for example, the alternating current controls. This poses a great challenge for the cognition, modeling, and analysis of the PEDPS. In this article, a nonlinear DAE model framework for the PEDPS is established with differential equations for the source nodes and algebraic equations for the dynamical electrical network, by generalizing the application scenarios of Kron reduction. The internal and terminal voltages of source nodes of converters are chosen as ports of nodes and network. Namely, the internal and terminal voltages of source nodes work as their output and input, respectively, whereas they work as the input and output of the algebraic network, respectively. The impact of dynamical network becomes clear, namely, it serves as a (linear) voltage divider and generates the terminal voltage based on the internal voltage of the sources simultaneously. By keeping only useful independent state variables, all differential equations for the transmission lines can be transferred to algebraic equations. With this simple model, the roles of both nodes and network become apparent, and it enhances the understanding of the PEDPS dynamics. On the other hand, broad simulations are conducted and compared to verify the proposed DAE framework for the PEDPS. As all independent variables have been kept in the model, it is found that they show the same computational accuracy, but better efficiency in computational time, compared to the electromagnetic‐transient simulation results.

Research on Channel Modeling Technology for Three Core Cables Based on Q3D

Abstract The modeling and analysis of power line channels are key to ensuring efficient and reliable power line carrier communication. In the past, the modeling of power line channels mainly relied on analytical methods to obtain unit length power line parameters. This method has a complex calculation process and requires high mathematical skills. This article presents a fast channel modeling method for three core cables. Firstly, the transmission function of a two port network with parallel cables as transmission lines is established. Then, a detailed scheme for extracting RLGC using Q3D software is proposed. Finally, the effectiveness of the proposed scheme is demonstrated through simulation analysis. This scheme is suitable for modeling complex shaped conductors and can reduce computational complexity, demonstrating significant advantages.

Design of a 240 elements antenna system for 5G massive MIMO applications with an inclined beam and two operating modes

A massive MIMO (multiple-input-multiple-output) antenna system for 5G base stations is developed, featuring 240 elements and 60 ports. The system supports two modes: individual port operation and network operation. It has a rectangular shape with dimensions of 28×16.8×0.32 cm³ and consists of three layers per side, with 15 ports per layer. Each port contains a 2×2 patch sub-array operating at 3.5 GHz, with beam tilting to generate uncorrelated radiation patterns. The system provides a measured bandwidth of 252 MHz, covering the 3.39–3.64 GHz band. Gain and envelope correlation coefficients are evaluated according to mMIMO parameters. A prototype is fabricated, and the results obtained through CST simulations are validated by experimental measurements.

Dynamic resilience analysis of the liner shipping network: From structure to cooperative mechanism

Liner shipping networks play a vital role in global and regional trade. However, they are susceptible to damage from unexpected interruptions, which can trigger dynamic cascading failures and undermine the system’s resilience. To address this challenge, we propose a novel cascading failure model for liner shipping networks that considers the characteristics of the network structure and port functions. First, we design two load redistribution methods that rely on network topology and employ a cooperative mechanism for coordination. This cooperative mechanism aims to balance the benefits for carriers and shippers by effectively controlling losses. Subsequently, we develop three metrics—network congestion rate, failure rate, and shipper loss—to assess the resilience of the network during cascading failures. To verify the impact of the cooperative mechanism, we apply the proposed methods to the China-Europe liner shipping network. Through simulations involving various port failures and resistance levels, we analyze the effectiveness of the cooperative mechanism. The results demonstrate that redistributing the load to downstream ports within the network effectively mitigates deep cascading failures. Additionally, the implementation of a port cooperative mechanism enhances resilience in the face of uncertainties by safeguarding crucial ports within the network and significantly reducing shipper losses. When port resistance is low, the cooperative mechanism reduces shipper losses by nearly half and lowers the average congestion rate. Although port reserve capacity can resist cascading failures, it falls short in the face of severe disruptions. In such cases, the cooperative mechanism compensates for capacity shortages, enhancing port resilience at a low cost. This study contributes to combating and minimizing cascading congestion in liner shipping networks, offering valuable insights for risk prevention and management strategies for ports and shipping companies. It also has implications for yield management and policy decisions from a network perspective.

Processes and mechanisms of the evolution of container port system in the Yangtze River Delta: An analysis from spatial and network perspectives

the Yangtze River Delta (YRD) has established a large-scale container port system with seaports and Yangtze ports as the mainstay and including other riverports and dry ports, occupying a prominent position in the pattern of national and even the global shipping development. Considering the new trend that the theoretical paradigm of port research has shifted from “spatial” to “network”, and that the focus of research goes from seaports to both seaports and inland ports, this study brings the complexity and uniqueness of the development of the port system in the YRD into the picture. By analyzing the influence of globalization, specialization, marketization, transportation, and greenization on port system development and its pattern formation, this paper elaborates on the gradient process of transportation and services allocation from the coast to the riverside and then to the inland. The evolution of port system is considered to have a temporal gradient between spatial-level transportation expansion and network-level services upgrading, and it is also believed that there is a spatial gradient in logistics supply chain terminalization between coastal and inland areas. Combined with the quantitative analysis from 200 5 to 2020, after entering the stage of port regionalization in the YRD, the container volume is distributed from coastal concentration to inland decentralization at the spatial level, while at the network level, port and shipping service enterprises (PSSEs) maintain a relatively centralized distribution along the coastal areas. At the same time, container volume growth rate fluctuates down, number of PSSEs growth rate fluctuates up, which trend is notable in the seaport. Currently, port regionalization in the YRD is still incomplete; the degree of logistics supply chain terminalization of ports in inland areas is relatively low; and the synergy between spatial and network in the entire YRD region has not yet been formed. This study tries to answer the question of the relationship between different types of ports in the complex port system, which can enrich the theoretical and empirical results of port system research and guide the practice of port and shipping in the YRD.

Resilience of regional container port network: based on projection correlation and dynamic spatial Markov Chain

ABSTRACT Ports are interconnected by shipping routes within the global logistics network. Shocks and risks stemming from financial crises, epidemics, ecology, and so on have prompted shifts in cross-border labor division towards regional cooperation, reflecting an ‘anti-globalization’ trend. Despite these dynamics, few studies have analyzed the spatial structure and dynamic evolution of resilience within regional container port network. Addressing this gap, this study considers spatial and dynamic attributes to identify influential factors of resilience and introduces the concept of spatial lag-multidimensional resistance (SL-MR) to strengthen the understanding and cognition of regional container port network resilience (RCPNR). By ports in Tianjin and Hebei, China, it constructs a dynamic spatial Markov chain (DSMC) based on the projection correlation (PC index) to dissect transition trajectories amid financial crises and other conflicts. The findings indicate: (1) The regional container port network often experiences a low-level path dependence like ‘poverty trap.’ (2) Hierarchical spatial lags significantly influence the transition probability of container port network resilience degradation, with regional port relationships being unidirectional rather than cooperative. (3) The impact of the 2008 financial crisis and the COVID-19 pandemic on regional port resilience varies, serving as key determinants in shaping diverse resilience types.

Effects of impedance matching network on α-γ mode transition in atmospheric pressure RF discharges

In atmospheric pressure RF discharges, positive and negative feedback regions are defined based on the influence of varying the capacitance of the series capacitor in an inverted L-type impedance matching network on the fed RF power at the input port of the impedance matching network. The impact of the impedance matching network on the α-γ mode transition was investigated by adjusting the tuning series capacitor in the impedance matching network. The critical RF power, as well as the current and voltage at the α-γ mode transition, is almost independent of the impedance matching network, while the counterpart immediately after the α-γ mode transition varies remarkably. The underlying mechanism is understood in terms of different feedbacks. Positive and negative feedbacks respectively promote and suppress the increment in RF power during the α-γ mode transition.

Tourist itineraries for Sustainable Mobility: an application in the Salento Area (Italy)

The purpose of this work is to define the design process, implemented through an analytical methodology, of two sustainable mobility tourist routes in a specific area of southern Italy (Salento); methodology applicable to other territorial realities. This design process was developed in the context of the 2014/2020 Interreg V-A Greece-Italy cross-border cooperation strategic project called "AI SMART_Adriatic Ionian Small Port Network". It takes into account the analysis of existing Plans and Programs at different levels (Sustainable Mobility Urban Plans; cycling routes; Territorial Plans, etc.), the analysis of statistical data in the area related to employment and tourism; the interlocution with key stakeholders, the analysis of architectural, landscape and food and wine surpluses. These routes have been defined for the interaction of the port of Otranto with the hinterland territories and with the opposite Ionian coast to promote the sustainable and inclusive transnational tourist fruition of the Apulian territory. The genesis of the two thematic itineraries stems from the need/willingness to valorise some areas of Salento through the connection of significant nodes in terms of landscape, architectural and historical value, which define two routes with Pulsano and Otranto as their vertices. The project brings together the potential of the Salento as an area with a strong tourist value, with the theme of sustainable mobility, suggesting the seasonality of travel of each, to meet the needs of deseasonalization of an area with a high summer and seaside tourism vocation.

Secured and Decentralized System for e-voting with Hybrid Cryptography and Blockchain

Electronic voting is an efficient way of conducting the voting process, which has the characteristics of real-time massive data which demands high security. In this paper, we propose a novel approach for electronic voting that utilizes decentralized network architecture with Blockchain and Hybrid cryptography techniques. Our system aims to address the challenges faced in administering EVMs and ensuring high security in strong rooms, which can lead to privacy and security flaws in the voting system. Our proposed model utilizes a wireless mesh topology to enlist vote details and modernize the chain of blocks, resulting in improved data confidentiality and reduced human resources. A customized UDP packet structure is designed to avoid port scanning and network traces, while the use of port numbers is eliminated for increased security. We also incorporate a three-layer encryption stack for secure key exchanges, which ensures perfect forward secrecy and an uncompromised state of the packet. By reducing the number of threads needed for Transport layer Protocol (TCP) connections; our proposed model improves the speed and security of the existing architecture. Overall, our approach offers a highly secure and efficient electronic voting system that meets the demands of secrecy, accuracy, and neutrality in the process of voting and counting. Our proposed system has the potential to prevent poll rigging by trespassers, ensuring a fair and trustworthy electoral process.

Modeling of direct AC/AC hybrid distribution transformer based on relaxed two port network theory

Traditional distribution transformers have shortcomings such as poor dynamic characteristics and unreasonable voltage compensation. It is difficult for them to meet the demand for power quality with the large-scale integration of new energy into the grid. Hybrid distribution transformers (HDTs) are an important means of addressing these issues. They have good flexibility in voltage regulation and huge development potential. To analyze the operating status and losses of an HDT, this study constructs a simplified equivalent impedance model for an HDT. First, the operating principle, characteristics, and voltage regulation range of a direct AC/AC HDT were analyzed. Second, based on the state–space averaging method, we obtain the HDT single-phase average circuit topology and construct an HDT relaxed two-port network model. Third, considering the operating losses of the transformer, Thevenin equivalent parameters of an HDT were derived. Then, a simplified equivalent impedance model for an HDT and the corresponding control strategies are presented. Finally, we verify the correctness and rationality of the proposed theory by constructing an HDT simulation model.

Biogeographic variation in environmental and biotic resistance modifies predicted risk of marine invasions by ships

IntroductionGlobal shipping has accelerated the spread of non-native species. Factors such as environmental filtering and interactions with local biota can affect invasion likelihood, yet their relative contribution to predicting invasion risk remains unresolved. To test how abiotic filters and an experimentally-derived measure of biotic resistance interact with propagule pressure, we developed an integrated model to evaluate their relative effects on invasion risk of marine biofouling organisms to different focal port regions. We predicted that environmental filtering impacts invasion risk when fewer but stronger connections are part of the network. Further, predation is a mechanism of biotic resistance, which can reduce invasion risk, with most pronounced effects predicted in the tropics that decline at higher latitudes.MethodsWe examined shipping traffic and predation impact at three coastal bioregions spanning 47-degrees of latitude al range in the Northeast Pacific (Alaska, California, and Panama). We used vessel traffic databases to characterize propagule pressure and construct a worldwide port network of marine shipping routes and ports. Environmental resistance was estimated using temperature and salinity data from donor and recipient regions. We further used standardized predator exposure experiments to quantify predation impact on fouling community biomass as an estimate of potential for biotic resistance. We then expanded on existing models of relative invasion risk to incorporate the probability that propagules will survive predation by local predators and overcome environmental filtering to generate a predicted invasion risk for each port.ResultsEnvironmental filtering in all regions and predation pressure in the tropics worked to reduce the invasion risk, resulting in markedly different cumulative risk profiles over time among regions.DiscussionIn an increasingly connected world with more vessel traffic, our results highlight that while the number and distribution of shipping routes are important to understand risk, abiotic and biotic filters can modify model predictions.

A study of the latest updates of the readout system for the hybird-pixel detector at HEPS

The High Energy Photon Source (HEPS) represents a fourth-generation light source. This facility has made unprecedented advancements in accelerator technology, necessitating the development of new detectors to satisfy physical requirements such as single-photon resolution, large dynamic range, and high frame rates. Since 2016, the Institute of High Energy Physics has introduced the first user-experimental hybrid pixel detector, progressing to the fourth-generation million-pixel detector designed for challenging conditions, with the dual-threshold single-photon detector HEPS-Beijing PIXel (HEPS-BPIX) set as the next-generation target. HEPS-BPIX will employ the entirely new Application-Specific Integrated Circuit (ASIC) BP40 for pixel information readout. Data flow will be managed and controlled through readout electronics based on a two-tier Field-Programmable Gate Array (FPGA) system: the Front-End Electronics (FEE) and the Input-Output Board (IOB) handle the fan-out for 12 ASICs, and the μ4FCP is tasked with processing serial data on high-speed links, transferring pixel-level data to the back-end RTM and μTCA chassis, or independently outputting through a network port, enabling remote control of the entire detector. The new HEPS-BPIX firmware has undergone a comprehensive redesign and update to meet the electronic characteristics of the new chip and to improve the overall performance of the detector. We provide an overview of the core subunits of HEPS-BPIX, emphasizing the readout system, evaluating the new hardware and firmware, and highlighting some of its innovative features and characteristics.

Development of multi-channel magnetic flux leakage testing system for bridge cables

Magnetic flux leakage (MFL) is one of the most popular techniques for detecting broken wire in bridge cables. MFL sensor array has attracted a lot of attention in recent years due to its capacity to measure the spatial distribution of the magnetic field of bridge cable. More sensors in the array lead to increased useful information extraction from the MFL field, allowing for more precise quantitative evaluation of bridge cable damage. This study reports the development of a cable MFL testing system capable of synchronous acquiring up to 512 channels of MFL sensors signal. Radial sensor arrays (RSA) composed of vertically placed magnetic sensors spaced at equal intervals are developed to be arranged around the bridge cable. They record the spatial distribution of the magnetic leakage field of the broken wire by collecting the MFL signal at various lift-offs. To solve the problem of multi- channel MFL signal synchronous acquisition, this study develops a MFL signal acquisition card based on multiplexing technology, capable of synchronous acquisition of up to 512 channels of MFL signal. Multiplexers are used to switch sensor channels, followed by multi-channel A/D conversion chips to convert the transmitted data. The converted data are temporally stored in the First-In-First-Out (FIFO) buffer of the Field Programmable Gate Array (FPGA) and transferred to the computer through the network port for display, storage, and signal processing. Finally, the motion control circuit, mechanical structure, and control software of the bridge cable MFL testing system are fully customized. Experiment results reveal that the system can be used in multi-channel MFL testing, laying the foundation for further multi-channel signal processing and bridge cable health evaluation.

Sustainable-resilient seaport-dry port network design considering inter-modal transportation

This paper proposes a multi-objective mathematical model for designing an inter-modal transportation network that includes a seaport and multiple dry-ports in both export-oriented and import-oriented modes under sustainability and resilience criteria. A multi-objective particle swarm optimization algorithm is tailored to solve the large-sized instances. The model and its solution method are validated through several numerical examples in different sizes whose results demonstrate that the development and design of such a seaport-dry port network is a critical component of the government's economic development while its development is a challenging issue requiring proper financing.

Tactical vessel deployment and empty container repositioning considering container turnover times

Global trade imbalances lead to the common occurrence of empty container flows from export-dominated to import-dominated ports in container shipping networks. Efficient strategies for repositioning empty containers are essential for addressing deficits at major ports. Existing studies often assume an arbitrary supply of empty containers at a port before repositioning. However, the actual quantity depends on laden containers shipped and turnover times. Considering this interdependence is crucial for reliable repositioning plans, especially at the tactical planning level.This paper explores an integrated problem of vessel deployment and empty container repositioning, aiming to deploy vessels along a route and periodically reposition empty containers, accounting for turnover times. We present an integer programming model minimizing operational and container shortage costs. A novel branch-and-price algorithm is developed, efficiently solving the master problem at each branching tree node using a novel approach that combines column generation and Lagrangian relaxation. Performance evaluation and computational experiments on instances generated from container port turnover statistics and shipping line operational data demonstrate the algorithm’s efficacy. The study highlights the impact of container turnover times on repositioning decisions, emphasizing the need for a comprehensive understanding of this dynamic in strategic planning.

Quantum filter routing of single photons

A quantum router takes the central role in an optical quantum network. However, how to route the expected photons with different frequencies to the targeted output ports of the quantum network is still a basic challenge. Here, we propose an effective approach, by setting the proper cavity-atom and photon-cavity chiral interactions, to realize quantum filter routing of single photons with different frequencies in a multi-channel quantum network. With the frequency serving as the signpost, the photons can be effectively routed to the targeted output ports by modulating the detunings between the cavities and the auxiliary atoms. Hopefully, this technique can play an important role in the construction of a highly efficient optical quantum network.

Phase Preservation of $N$-Port Networks under General Connections

Phase Preservation of $N$-Port Networks under General Connections

OVERVIEW OF FRAUD DETECTION SYSTEMS AND PERFORMANCE KPI DEVELOPMENT

In this article overview was provided on several fraud detection systems, analysis result of common scheme and development of KPIs to detect performance degradation or improvement from business logic point of view. Four different systems were reviewed. Following FMS were developed by Gigamon and Argyle Data cooperation, AWS, Subex, Cvidya Amdocs. Solution developed by Gigamon and Argyle Data consists of Gigamon fabric for information collection/filtering/enrichment and Argyle Data Fraud detection system, which is based on Hadoop technology to store collected data and analysis results by application. AWS Fraud Detection collects NRTRDE flow and process it by using ML technics provided by AWS. Subex fraud management system provides flexible ETL for data collection from different sources with adjustable detection rules and ML for suspicious behavior learning. FraudView by Cvidya Amdocs collects information from varying points like OSS/BSS, CRM customer details, Prepaid platforms, HLR, Switch CDRs, Probe (SS7, VoIP, IP) and process it by different detection engines. Simplified processing FMS processing scheme and KPIs based on different timestamps were made. Following conclusions were made: In reviewed FMS was noticed that instead of using traditional NRTRDE and TAP3 file formats, data can be collected directly from network by using network tap or port mirroring with next data enrichment, cleaning, formatting for fraud detection system to consume. Following real time method can be realized by using probes to perform data preparation or some complex solution described by Gigamon; Detection is performed by rules, provided by vendor or by ML modules, which learns behavior of subscriber in order to create detection rules. Most of systems allow to modify threshold of following rules in order to meet system user demands to check data within specific time (for example fraudster night calls to subscriber) or detect specific number of suspicious sessions, etc; In order speedup fraud detection hotlists, whitelists can be used for enrichment to filter out fraudsters, emergency or business numbers. Geographical location can be used to identify fraudster’s location within network and make correlation with other possible fraud sessions; During analysis of each FMS architecture, 3 processing stages were highlighted, which allowed to create simple KPIs for business logic and data arrival check; Developed methodology allows to check data arrival and fraud recognition with used data type to define which information provides better detection or view on rules for detection in order to show, which of them should be adjusted.