Net Theory Research Articles

Deterministic fault-tolerant connectivity labeling scheme

AbstractThe f-fault-tolerant connectivity labeling (f-FTC labeling) is a scheme of assigning each vertex and edge with a small-size label such that one can determine the connectivity of two vertices s and t under the presence of at most f faulty edges only from the labels of s, t, and the faulty edges. This paper presents a new deterministic f-FTC labeling scheme attaining $$O(f^2 \textrm{polylog}(n))$$ O ( f 2 polylog ( n ) ) -bit label size and a polynomial construction time, which settles the open problem left by Dory and Parter (in: Proceedings of the 2021 ACM symposium on principles of distributed computing (PODC), pp 445–455, 2021). The key ingredient of our construction is to develop a deterministic counterpart of the graph sketch technique by Ahn et al. (in: Proceedings of the 31st ACM SIGMOD-SIGACT-SIGAI symposium on principles of database systems (PODS), pp 5–14, 2012), via some natural connection with the theory of error-correcting codes. This technique removes one major obstacle in de-randomizing the Dory–Parter scheme. The whole scheme is obtained by combining this technique with a new deterministic graph sparsification algorithm derived from the seminal $$\epsilon $$ ϵ -net theory, which is also of independent interest. As byproducts, our result deduces the first deterministic fault-tolerant approximate distance labeling scheme with a non-trivial performance guarantee and an improved deterministic fault-tolerant compact routing. The authors believe that our new technique is potentially useful in the future exploration of more efficient FTC labeling schemes and other related applications based on graph sketches.

Program Dependence Net and on-demand slicing for property verification of concurrent system and software

When checking concurrent software using a finite-state model, we face a formidable state explosion problem. One solution to this problem is dependence-based program slicing, whose use can effectively reduce verification time. It is orthogonal to other model-checking reduction techniques. However, when slicing concurrent programs for model checking, there are conversions between multiple irreplaceable models, and dependencies need to be found for variables irrelevant to the verified property, which results in redundant computation. To resolve this issue, we propose a Program Dependence Net (PDNet) based on Petri net theory. It is a unified model that combines a control-flow structure with dependencies to avoid conversions. For reduction, we present a PDNet slicing method to capture the relevant variables’ dependencies when needed. PDNet and its on-demand slicing in verifying linear temporal logic are used to significantly reduce computation cost. We implement a model-checking tool based on PDNet and its on-demand slicing and validate the advantages of our proposed methods.

Constructing Sukuk-linked Awqaf (endowment) model

PurposeIslamic endowment (awqaf), particularly awqaf land, is one of the potential Islamic social assets to serve the public interest, particularly to provide public infrastructures such as business centers, public hospitals and airports. However, unfortunately, most of them are still unproductive lands, especially in the form of idle lands. One problem to use such unproductive awqaf lands is the lack of awqaf land model as the platform to use such awqaf lands. This paper aims to construct and propose a model called Sukuk-linked Awqaf (SLA) to use awqaf lands as an underlying for Sukuk issuance.Design/methodology/approachThis paper constructs mechanisms and formulas of SLA by involving Sukuk issuer, awqaf management (Nadzhir), Sukuk investors and tenants of the infrastructure. In particular, the SLA model is proposed based on the unique characteristics of both awqaf asset and Ijarah (leasing) Sukuk, considers the intention of state-owned enterprise (SOE) to construct buildings to be rented to the tenant and to be owned by the awqaf manager and formulates equations and uses net present value theory to determine Nadzhir and Sukuk investors’ investment decisions.FindingsEngaging awqaf land with SLA model can ease its benefit for the society. The model addresses the strategic roles of Nadzhir, SOE, investors and contractor in using awqaf land.Research limitations/implicationsThe SLA model could ease related parties to use the awqaf land for the sake of public benefits.Originality/valueTo the best of the author’s knowledge, this is the first assessment on the potential implementation of Islamic hedging with a commodity as an alternative hedging in Indonesia.

Analysis and optimization of a Stochastic Petri Net for air-rail intermodal transportation.

Air-rail intermodal transportation (ARIT) plays a crucial role in China's intermodal transportation system. This study aims to model and optimize issues such as inefficiency and complexity in China's ARIT freight transportation using Business Process Reengineering and Stochastic Petri Nets theories. The Petri Net (PN) model for incoming freight transport in ARIT is based on actual operations, employing a new method involving Stochastic Petri Nets and isomorphic Markov Chains theory for performance analysis. Performance analysis results help intuitively identify areas needing optimization. Based on optimization principles, elements such as railway container packaging are improved, resulting in an optimized PN model for ARIT. Finally, data analysis shows that the optimized ARIT model reduces total delay by 7.7% compared to the original. This demonstrates that the new method, combining Markov Chain performance analysis and optimization principles, is feasible and effective for ARIT optimization.

Fusion and Positivity in Chiral Conformal Field Theory

In this article we show that the conformal nets corresponding to WZW models are rational, resolving a long-standing open problem. Specifically, we show that the Jones-Wassermann subfactors associated with these models have finite index. This result was first conjectured in the early 90s but had previously only been proven in special cases, beginning with Wassermann’s landmark results in type A. The proof relies on a new framework for the systematic comparison of tensor products (a.k.a. ‘fusion’) of conformal net representations with the corresponding tensor product of vertex operator algebra modules. This framework is based on the geometric technique of ‘bounded localized vertex operators,’ which realizes algebras of observables via insertion operators localized in partially thin Riemann surfaces. We obtain a general method for showing that Jones-Wassermann subfactors have finite index, and apply it to additional families of important examples beyond WZW models. We also consider applications to a class of positivity phenomena for VOAs, and use this to outline a program for identifying unitary tensor product theories of VOAs and conformal nets even for badly-behaved models.

Modeling and Analyzing the Strategy Game “Factorio” Using Modular Petri Nets and the General-Purpose Petri Net Simulator

The video game Factorio is a popular real-time strategy game that hosts a variety of gameplay scenarios analogous to real-world problems such as factory building, pipeline optimization, and conveyor belt logistics. It also considers environmental costs such as pollution and energy consumption. This game focuses on automation and resource management within the context of creating and maintaining factories. Players are challenged to design efficient factories, automate production, control energy consumption, and balance resource utilization, all while defending against environmental challenges such as pollution and hostile enemies. Factorio is a complex software; however, studies have demonstrated its ability to enhance student satisfaction when integrated as an educational module at the university level. This paper aims to utilize the power of Petri Net theory and the practical tool GPenSIM to model and simulate several Factorio pipelines and score them against one another, exploring which pipeline configuration is optimal. The primary objective is to make a mathematical model (Petri Net) to better understand the game’s complex mechanisms, identify bottlenecks within the system, and explore opportunities for optimization within the network of modules. The insights gained from this paper may find practical applications in real-world scenarios.

B\"{a}cklund transformations as integrable discretization. The geometric approach

We present interpretation of known results in the theory of discrete asymptotic and discrete conjugate nets from the "discretization by B\"{a}cklund transformations" point of view. We collect both classical formulas of XIXth century differential geometry of surfaces and their transformations, and more recent results from geometric theory of integrable discrete equations. We first present transformations of hyperbolic surfaces within the context of the Moutard equation and Weingarten congruences. The permutability property of the transformations provides a way to construct integrable discrete analogs of the asymptotic nets for such surfaces. Then after presenting the theory of conjugate nets and their transformations we apply the principle that B\"{a}cklund transformations provide integrable discretization to obtain known results on the discrete conjugate nets. The same approach gives, via the Ribaucour transformations, discrete integrable analogs of orthogonal conjugate nets.

Destructive Ability Analysis of Genetic Algorithm Operator When Solving Business Process Problem of Structural and Parametric Synthesis

The work analyzes the destructive ability of operators of a classical genetic algorithm when solving the problem of controlling the trajectory of a population during the search for solutions. In accordance with the hypothesis put forward, when solving the problem of structural-parametric synthesis of large discrete systems with a given behavior, it is advisable to change the settings of the functioning of the genetic algorithm operators to ensure: better convergence of the genetic algorithm, avoid attenuation, signal the need to restart the solution synthesis procedure, and also facilitate the derivation of the population from local extrema. It is proposed to use an artificial neural network as a control element (control add-on), which should implement control of the process of synthesis of simulation models of business processes based on a given behavior (the ability of a simulation model to convert a given input vector into a reference output), which is especially important when working with large systems. In accordance with the same hypothesis, an increase in the destructive ability of the crossing over and mutation operators allows the population to be dispersed across the solution space, which is advisable when attenuation occurs and is in a local extremum, and a decrease in the destructive ability contributes to a more thorough search for solutions in a certain area of the solution space. The paper provides examples of the work of operators and the behavior of the population when synthesizing simulation models of business processes based on the theory of Petri nets. To model the operation of a genetic algorithm and an artificial neural network, it is proposed to use the theory of Petri nets, which simplifies the process of managing the synthesis procedure and allows the use of parallel programming tools with distributed GPGPU computing on CUDA technology. As part of this study, an analysis of the behavior of the population when changing the operating settings of operators was carried out, which confirmed the hypothesis put forward.

Security Evaluation and Improvement of the Extended Protocol EIBsec for KNX/EIB

The European Installation Bus(EIB) protocol, also known as KNX/EIB, is widely used in building and home automation. An extension of the KNX/EIB protocol, EIBsec, is primarily designed to meet the requirements for data transmission security in distributed building automation systems. However, this protocol has some security issues in the request, key distribution, and identity authentication processes. This paper employs a formal analysis method that combines Colored Petri Net (CPN) theory with the Dolev-Yao attack model to evaluate and enhance the EIBsec protocol. It utilizes the CPN Tools to conduct CPN modeling analysis on the protocol and introduces a security assessment model to carry out intrusion detection and security assessment. Through this analysis, vulnerabilities in the protocol, such as tampering and replay attacks, are identified. To address these security concerns, we introduce hash verification and timestamp judgment methods into the original protocol to enhance its security. Subsequently, based on the improved protocol, we conduct CPN modeling and verify the security of the new scheme. Finally, through a comparison and analysis of the performance and security between the original protocol and the improved scheme, it is found that the improved scheme has higher security.

Key Therapeutic Targets to Treat Hyperglycemia-Induced Atherosclerosis Analyzed Using a Petri Net-Based Model.

Chronic superphysiological glucose concentration is a hallmark of diabetes mellitus (DM) and a cause of damage to many types of cells. Atherosclerosis coexists with glucose metabolism disturbances, constituting a significant problem and exacerbating its complications. Atherosclerosis in DM is accelerated, so it is vital to slow its progression. However, from the complex network of interdependencies, molecules, and processes involved, choosing which ones should be inhibited without blocking the pathways crucial for the organism's functioning is challenging. To conduct this type of analysis, in silicotesting comes in handy. In our study, to identify sites in the network that need to be blocked to have an inhibitory effect on atherosclerosis in hyperglycemia, which is toxic for the human organism, we created a model using Petri net theory and performed analyses. We have found that blocking isoforms of protein kinase C (PKC)-PKCβ and PKCγ-in diabetic patients can contribute to the inhibition of atherosclerosis progression. In addition, we have discovered that aldose reductase inhibition can slow down atherosclerosis progression, and this has been shown to reduce PKC (β and γ) expression in DM. It has also been observed that diminishing oxidative stress through the inhibitory effect on the AGE-RAGE axis may be a promising therapeutic approach in treating hyperglycemia-induced atherosclerosis. Moreover, the blockade of NADPH oxidase, the key enzyme responsible for the formation of reactive oxygen species (ROS) in blood vessels, only moderately slowed down atherosclerosis development. However, unlike aldose reductase blockade, or direct PKC (β and γ), the increased production of mitochondrial ROS associated with mitochondrial dysfunction effectively stopped after NADPH oxidase blockade. The results obtained may constitute the basis for further in-depth research.

Form-finding of elastic gridshell based on spatial elastica model

In engineering design, elastic gridshells, which are composed of a number of elastic rods, are advantageous because they are lightweight, easy to construct, and low-cost as well as have a long-span space. However, the form-finding of a gridshell is challenging owing to the large deformation and strong geometric-nonlinearity of the structure.In this paper, a new form-finding method based on spatial elastica model (FMSE) is proposed. The deformations of elastic rods, obtained via the elliptic integral solution of spatial elastica, is integrated into the overall deformation of the gridshell. A set of transcendental equations is solved using the quasi-Newton method to ensure that the deformation of the gridshell satisfies the given boundary conditions. To validate the proposed FMSE method, desktop experiments (designed using the theory of Chebyshev nets) are performed on gridshells made of glass fiber reinforced polymer rods. The predictions of the FMSE method agree well with the experimental results.Accordingly, the proposed FMSE method is expected to have potential applications in elastic gridshells, on the investigations of form-finding, load-bearing capability, non-local deformation behavior, and also stability of structures.

Modeling and efficiency analysis of blockchain agriculture products E-commerce cold chain traceability system based on Petri net

The cold chain supply chain of e-commerce has the characteristics of long chain, dispersed production, heterogeneous information sources, etc., which is easy to cause the upstream and downstream information of the supply chain to be broken and opaque. Traditional traceability data is stored in each node enterprise, and there are problems such as low cooperation trust and poor authenticity in the upstream and downstream data transmission process of the supply chain, resulting in consumers' trust crisis on the authenticity of traceability information. Blockchain traceability system through the establishment of multi-party participation, joint maintenance of distributed database, and the use of cryptography and consensus mechanism to establish trust relationships, with data can not be tampered with, sharing of high credibility. On the basis of stochastic Petri net theory, this study constructed a blockchain e-commerce cold chain traceability model centering on the actual application of blockchain technology in logistics traceability to improve the reliability and validity of e-commerce cold chain traceability. Correlation matrix and invariants were used to analyze the validity of the model, and an isomorphic Markov chain was constructed to analyze the effectiveness evolution of the model. This study aims to deepen the understanding of the cold chain traceability system of blockchain e-commerce from the three aspects of the best optimization link, the best synergism scale, and the adaptive ability of the system to provide reference for the improvement of cold chain traceability ability by blockchain technology.

Mental workload evaluation model of receiver aircraft pilots based on multiple resource theory

AbstractAerial refueling is an extender of air combat capability that has received widespread attention with the development of the military field, particularly the mental workload of the pilot performing the aerial refueling task, as it is the key to the aerial refueling success rate. Therefore, this study analyzes the behavior of receiver aircraft pilots from rendezvous to the separation phase and constructs a mental workload model to improve the aerial refueling success rate. First, the time‐channel‐action unit network was constructed based on Petri net and multiple resource theory (MRT). Second, the mental workload evaluation model was constructed from three dimensions: conventional resource occupation, additional resource occupation, and time occupation. Finally, a simulated experiment was conducted, and the results showed that the mental workload obtained by the model constructed in this study exhibits a high positive correlation with subjective mental workload, pupil diameter, and blink rate, surpassing the accuracy of the traditional MRT model.

Stability of dyadic exchange: Experimental evidence for the impact of shared group membership

Pair stability refers to the extent to which exchange occurs between the same actors over time. In a stable pair, actors know what to expect of one another and have a sense of predictability as to the outcome of the exchange. When actors are split into discrete groups, shared group membership contributes to formation of new ties and maintenance of existing ties due to the mechanism of attraction to similar others. Using the formal framework of biased net theory, we propose three hypotheses which link shared group membership with the odds of pair stability. These hypotheses are tested against data from an experiment (N = 180) in which participants were first split into two groups and then given a series of opportunities to share resources with one another. Results of the experiment are consistent with the hypotheses.

Analysis of Green Closed-Loop Supply Chain Efficiency under Generalized Stochastic Petri Nets

In this paper, we aim to explore the operational performance of a green closed-loop supply chain under random events. A green closed-loop supply chain model based on generalized stochastic Petri nets (GSPN) is built using the Petri nets theory. According to the isomorphic relationship between GSPN and continuous-time Markov chains, the relevant Markov model is converted from GSPN, and the steady-state probability of the model is then calculated. Finally, the model is analyzed from the aspects of time performance and operation efficiency of each link. Compared to previous studies, this paper finds that: when the whole green closed-loop supply chain system reaches a dynamic equilibrium state, the product has a steady-state probability at all stages, and thus the overall operational performance of the system can be obtained; compared with the recycling of waste products, the green product takes a longer time in the production and distribution stages; since marketing, packaging processing, market feedback, and market demand formulation account for a high level of utilization throughout the life cycle of green products, decision makers need to focus on the supervision and management of these links. Managers of green closed-loop supply chain systems need to adjust their decision-making strategies in a timely manner according to the performance level of the system in the steady state to realize the efficient operation of the system. This paper not only provides theoretical support for the improvement of the operational efficiency of green closed-loop supply chain system, but also provides new ideas for the research of green closed-loop supply chain operation mode.

PENGARUH PIUTANG MURABAHAH TERHADAP LABA BERSIH BANK SYARIAH INDONESIA (BSI) PERIODE 2021-2022

Bank Syariah Indonesia, which is known by the public, is a financial institution that oversees sharia principles. On February 1, 2021 Bank Syariah Indonesia (BSI) was the result of the merger of Bank Syariah Mandiri, Bank BRI Syariah and Bank BNI Syariah. At the same time, Bank Syariah Indonesia (BSI) released its developer product, namely murabahah financing. Murabaha financing objects whose development tends to increase from time to time. On the basis of seeing an increase in murabahah financing every year the author wants to know whether this increase has an effect on net profit at Bank Syariah Indonesia (BSI). The purpose of this research is to find out and partially describe murabahah receivables on net profit at Bank Syariah Indonesia (BSI) for the 2021-2022 period. This study uses the product theory from Adiwarman A. Karim (2008) which states that murabaha financing is the sale and purchase of goods at the original price with additional profits agreed between the bank and the customer and the net profit theory from (Kasmir, 2014) which states net profit as the difference between revenue minus costs incurred for business purposes and minus taxes. This research method is a quantitative method with secondary time series data, namely the monthly reports of Bank Syariah Indonesia (BSI) for the 2021-2022 period. Sampling using purposive sampling technique. Analyzed with the classical assumption analysis method, simple linear regression, hypotheses and processed with SPPS software version 25. The results of this research show that the acquisition of the t test results is tcount (2.492) > ttable value, (2.085). The result of the test for the coefficient of determination is the R square of 0.220 (22%). Which means that murabahah receivables have an influence of 22% on the net profit of Bank Syariah Indonesia (BSI). The hypothesis states that murabahah receivables (Variable X) have a positive and significant effect on net income (Variable Y).

СЕТЕВОЕ МОДЕЛИРОВАНИЕ ПРОЦЕССА АНАЭРОБНОГО СБРАЖИВАНИЯ НАВОЗА

The article discusses the technological complex of anaerobic digestion of manure (ASN). Thanks to biogas plants, it is possible to mitigate the harmful effects on reservoirs and their inhabitants, reduces pollution with ammonium salts and restores the natural oxygen saturation of waters. The effectiveness of the functioning of such systems can be ensured with the help of modern methods of information processing, using methods of system analysis of complex objects based on a mathematical description of the technological process. Based on the review of the main methods of modeling discrete-continuous chemical-technological systems (CTS), the expediency of using the apparatus of the theory of Petri nets (SP) for process modeling (ASN) is substantiated. To describe the system, we propose the use of N–schemes based on the mathematical apparatus of Petri nets, one of the advantages of which is the possibility of presenting the network model both in analytical form, with the possibility of automating the analysis process, and in graphical form to ensure the visibility of the model being developed. When analyzing chemical-technological schemes, the main limitation of the N–scheme formalism should be taken into account, which is that they do not take into account the time characteristics of the simulated systems, since the transition response time is considered to be zero. Taking into account these conditions, we have proposed modified Petri nets focused on modeling and analysis of discrete-continuous CTS by including priority transitions, delay time of labels in positions and transitions. A model in the form of a modified Petri net (SME) is constructed. By means of the TRACE MODE SCADA technology, a software package of the process control system (ASN) has been developed. The process control system allows you to perform dispatching control of the main elements of the control system, stop the system (ASN) and analyze its condition, both as a whole and in order to predict the development of emergency situations.

An ETCEN-Based Motion Coordination Strategy Avoiding Active and Passive Deadlocks for Multi-AGV System

In recent years, automated guided vehicles (AGV) are widely used to sort and transport parcels in logistics warehouses. The deployment of AGVs can improve storage efficiency and free human labour greatly. However, as the number of AGVs grows, the computational complexity and deadlock occurrence rate increase simultaneously, making it extremely difficult to coordinate AGVs’ movements in real time. In this paper, we first present a hierarchical motion coordination system based on event-triggered colored elementary net (ETCEN). The primary aim of the system is to coordinate AGVs in real time regardless of the system’s scale. Then, we describe deadlocks by the ETCEN model and classify them into two categories - active deadlocks and passive deadlocks. Active deadlocks are prevented dynamically by controlling the movements of AGVs, while passive deadlocks are resolved by an improved path planning strategy. The entire system relies on a two-layer architecture, thereby improving flexibility and scalability. The proposed algorithms are validated by simulations and applications. Experiment results demonstrated that our approach can coordinate multi-AGV systems, avoid collisions and prevent deadlocks effectively. Note to Practitioners—This paper was motivated by the problem of coordinating multi-AGV system in warehouses, especially the tricky problem of preventing deadlocks in large-scale applications. Existing approaches mainly focused on collision-avoiding strategies, while paying less attention to the deadlock-preventing problem. As a result, the feasibility of current deadlock prevention methods strongly depends on the topology of the environment, and the computation time will surge exponentially as the scale of AGVs grows. This paper suggests a general approach towards solving two types of deadlocks (active deadlocks and passive deadlocks) based on Petri net theory. In this paper, a multi-AGV coordination model is presented and described thoroughly. Then we use the model to prove our theories and introduce our collision-avoiding and deadlock-preventing strategies. A two-layer architecture is designed to support the expansion of AGV fleet, making our system highly scalable. Both experiments and applications suggest that this approach is feasible and effective. In future research, we will focus on further optimizing the coordination and routing algorithm to improve the system throughput.

Dynamic well killing method based on Y-tube principle when the drill bit is off-bottom

The design of dynamic well killing parameters lacks theoretical support because the U-tube principle is not applicable while drilling bit is not at the well bottom. We present the Y-tube principle and establish a gas and liquid two-phase flow model with the killing fluid backflow and zero net liquid flow theory in wellbore below the drill bit. A dynamic well killing theory is proposed, and the variations of the well killing parameters are revealed. The results were as follows. (1) The Y-tube was composed of an annular part above the bit, a drillstring part, and a wellbore part below the bit. Gas–liquid flow models in those three parts were established to accurately simulate the dynamic well killing process when the drill bit was off-bottom. (2) Based on these models, the dynamic inflow and outflow curves during the killing period were obtained. The variations of the dynamic well killing parameters were analyzed by comparing the two curves. (3) With the increase of pressure, the critical gas velocity of blowout decreases, while the temperature, density and viscosity of the killing fluid do the opposite. With the increase of temperature, density and viscosity, and the decrease of the wellbore diameter, the bottom hole pressure increases. And it decreases with the decrease of the distance between the bit and wellhead. (4) Considering the actual well killing conditions, it is recommended to increase the critical blowout velocity by increasing the killing fluid surface tension and density, and to change the killing fluid density and viscosity so that the dynamic outflow curve is always above the dynamic inflow curve or the dynamic outflow curve is always above the formation pressure. As a result, the dynamic well killing will be successful when the bit is not at the well bottom.

Evaluation and Improvement of Internet Printing Protocol Based on HCPN Model Detection Method

The Internet Printing Protocol (IPP) is a bridge between hosts and printers, and is supported by more than 98 percent of printers today. In addition to supporting local use, the IPP protocol also supports online use. Although this can expand the scope of its application, it has also introduced potential risks to user data. IPP has security components that should be able to guarantee confidentiality, integrity, and non-repudiation. In order to verify whether its security components can achieve this goal, this study modeled the 0-RTT authentication process of the IPP protocol based on Petri net theory and CPN Tools, introducing the improved Dolev–Yao adversary model to perform security evaluation on the protocol model. The result showed that the server could not resist the adversary’s replay attacks on early data. Accordingly, we proposed an improved authentication scheme that introduced a random number signature to enhance the server’s anti-replay capability. Using the same attack model to verify, the result proved that the new scheme was feasible and effective. The method used in this article could easily observe the movement of the security protocol message flow and the specific actions of each participant (including the adversary), which ensured researchers could easily locate the protocol defects and make improvements.