Qualitative Simulation Research Articles

Mitigating foreign exchange risk exposure with supply chain flexibility: A real option analysis

AbstractUncertainty and risk abound in supply chains. One such form of risk existing in global supply chains comes from volatility associated with currency fluctuations—Foreign Exchange (FX) risk. Although the study and practice of using financial hedging instruments are well documented, there are also emerging supply chain strategies firms may adopt for mitigating FX risk. The purpose of this multi‐method study is to investigate how supply chain professionals perceive and mitigate FX risk, as well as to measure how investing in supply chain flexibility strategies affect firm financial performance. Using a mixed‐method approach based on qualitative case studies and simulation experiments using the lens of Real Option Theory, we are able to show how investments in supply chain flexibility strategies can mitigate FX risk in terms of cash flows and profits. Theoretical, methodological, and managerial implications are provided for better understanding FX risk in the emerging supply chain finance discipline.

Mesoscale simulations of spherulite growth during isothermal crystallization of polymer melts via an enhanced 3D phase-field model

A finite difference-based 3D phase-field model is developed to investigate the spherulite growth at the mesoscopic scale during the isothermal crystallization of polyamide (PA) 12. The model introduces a phase-field variable to distinguish the crystalline and amorphous phases of polymers. The phase-field evolution equation is coupled with the heat conduction equation that considers the latent heat of crystallization. The evolution equations introduce both the dimensionless diffusivity and latent heat that are dependent on the crystallization temperature. A high-order finite difference-based numerical framework is applied to the phase-field model. Both the qualitative simulation results of the phase-field model such as the crystal morphologies and the quantitative results including the radial crystal growth rate, degree of crystallinity, and lamellar thickness are validated against experiments. The simulation for single-crystal growth shows that a high crystallization temperature results in a large crystal with a slow radial growth rate. The simulation for multi-crystal growth shows that the crystals impinge on each other and finally fill the whole domain during crystallization, which further demonstrates the capability of the model in simulating the spherulite growth during isothermal crystallization of polymer melts.

Preparation and properties of bio-based self-healing fire prevention gel reinforced with expanded graphite ligand

This study aims to facilitate fire prevention and extinguishing in coal mines through the use of peanut shells, a kind of agricultural waste. To this end, cellulose nanofibrils (CNF) extracted from peanut shells were mixed with polyvinyl alcohol (PVA), boric acid (borax), expanded graphite (EG) and NaHCO3 for preparing new self-healing PVA-borax-CNF/EG fire prevention (FP) gel. The Fourier transform infrared spectroscopy results suggest that CNF, PVA and borax have experienced copolymerization, forming many hydrogen bonds. By observing the scanning electron microscope images, it can be found that the three-dimensional structure of FP gel is orderly arranged, and the gel contains many pores and folds in which various elements are evenly and densely distributed. Product performance experiments show that the water absorption rate of PVA-Borax-CNF/EG in distilled aqueous solution is 435 times; the resistance rates of C2H4 and CO2 are 47.55% and 51.13% respectively; in addition, the combustion of PVA-Borax-CNF/EG mixed samples termination time is extended by about 109 s, indicating that it will not affect the calorific value of coal combustion. Significantly, there is a lack of studies on the action mechanism of FP gel and coal, and the FP mechanism of PVA-borax-CNF/EG is explained by the qualitative MS simulation method in this paper. PVA-borax-CNF/EG flame retardant can effectively control the oxidation of coal seams and reduce the temperature of coal, thus ensuring the physical and mental health of coal workers.

Effect of galvanostatic anodic polarization on hydrogen evolution rate and residual fatigue strength of Mg alloys for implant use

For surgery, biodegradable magnesium alloys are considered promising candidates. The low corrosion resistance is advantageous since the implant is degraded in the presence of aqueous body fluids, supporting the human bone for a defined time and be fully degraded after this functional phase, making a second surgery for implant removal unnecessary. To design this phase and prevent early implant failure, precise knowledge of the degradation behavior over months and the correlating mechanical stability is essential. In vitro tests of the required duration are associated with enormous time and cost efforts. Therefore, a short-time method is developed to accelerate the degradation progress by anodic polarization without affecting the corrosion mechanism. The method is based on the corrosion behavior of Mg alloys under polarization, accompanied by increasing hydrogen evolution for increasing current densities, allowing conclusions to be drawn about the corrosion rate. Three-week immersion tests of the alloy WE43 with and without plasma electrolytic oxidation are the starting point. The time-dependent corrosion rates are to be reproduced by applying anodic polarization within three days. An experimentally determined relationship between current density and corrosion rate is used to design the polarization. The corrosion morphology of both testing strategies is analyzed by µCT. To evaluate the influence of the morphology on the mechanical stability, ex situ multiple amplitude tests are performed, allowing an estimation of the residual fatigue strength. The results show that a qualitative simulation of the hydrogen evolution rate is possible by applying polarization, achieving an enormous time saving. Due to a changed corrosion morphology with increased pitting tendency and the associated reduced residual fatigue strength, the method has to be considered as a worst-case evaluation allowing to exclude unsuitable Mg-based biomaterials right from the beginning, in particular before further preclinical studies.

Monitoring and Simulation Study on Shrinkage Behaviour of Steel-UHPC Composite Deck

Combining an Ultra-High Performance Concrete (UHPC) layer with an orthotropic steel bridge deck by stud connectors could enhance the fatigue performance of a deck system because of the improved system stiffness. However, UHPC is featured by significant early-term shrinkage owing to the material composition. Inappropriate constraints introduced by stud connectors may result in a high risk of UHPC cracking, leading to unexpected safety and durability issues. This study investigated the early-term shrinkage behaviour of a steel-UHPC composite bridge deck by conducting an 80-day shrinkage monitoring test at first. The monitoring results showed that the UHPC hardening process lasted for over 44 h, and the maximum UHPC shrinkage under constraint in the composite deck was only 120 μϵ, while the shrinkage induced compressive stress on the steel deck plate reached 36 MPa. Meanwhile, qualitative simulation and parametric analysis works were carried out to investigate structural dimension effects on shrinkage behaviour of the composite bridge deck in detail. According to the analysis results, the UHPC shrinkage and the induced stress on the steel deck plate had obvious uneven distribution feature. And stud spacing was found as a sensitive factor to shrinkage constraint extent compared with rebar spacing and stiffener thickness. Therefore, a rational stud spacing and design suggestions for practical applications were discussed in addition.

Analysis of intellectual property cooperation behavior based on stochastic catastrophe theory and the QSIM algorithm

This article introduces a new model, the catastrophe model of intellectual property cooperation behavior. The purpose of the model is to analyze the evolutionary track of intellectual property cooperation behavior. After providing a general of catastrophe mechanism of intellectual property cooperation behavior and introducing stochastic catastrophe theory, this article offers a catastrophe model of intellectual property cooperation behavior. And then, based on the survey data of high-tech enterprises, the model parameters were given by introducing the qualitative simulation algorithm. The results demonstrate that intellectual property cooperation is composed of a cooperation strategic planning stage, cooperation system formation stage, cooperation system working stage, and cooperation profit distribution stage. Under the influence of control variables, the intellectual property cooperation behavior will appear catastrophic near the set of bifurcation points. Most previous studies on intellectual property cooperation have disregarded the characteristic of the sudden changes in cooperation behavior. Therefore, this article offers an integrated catastrophe model and explains the nature of intellectual property cooperation behavior.

FEATURES OF MANAGEMENT OF ECONOMIC SUSTAINABILITY IN THE MANAGEMENT SYSTEM OF THE ENTERPRISE

The article systematizes scientific views on the definition of enterprise sustainability management approaches. Literary sources related to the study of enterprise sustainability management are analyzed. The work proves that the solution to the tasks of ensuring the economic stability of the enterprise requires a combination of systematic methods of qualitative analysis, simulation modeling, and optimization methods of inventory management. A number of principles for choosing management methods and influencing certain factors of the internal and external environment are substantiated. Since management actions aimed at ensuring the appropriate level of economic sustainability should be based on the results of a comprehensive analysis, the work has developed a sequence of economic sustainability management, which covers all elements of the proposed functional dependence that models the sustainability of the enterprise. The basis of the analysis of the prerequisites for ensuring sustainability should be methods of assessing the impact of the external environment on the sustainability of the enterprise. The tasks that the process of managing the economic sustainability of the enterprise must solve are formulated. On the basis of the analysis, the purpose and task of managing the economic stability of the enterprise is determined, the main of which can be defined as the identification of the causes and main factors of ensuring financial stability, the purposeful search for techniques and methods of financial stability management. The characteristics of economic sustainability management are given as one of the most important tasks of financial management of enterprises in modern economic conditions. It has been proven that increasing the efficiency of the enterprise depends on the validity, timeliness and expediency of the management decisions made in this area. The expediency of applying a systemic approach to managing financial stability as an approach that allows taking into account the influence of internal and external factors on the state of the company's finances is substantiated. The problem of financial problems faced by machine-building enterprises is described. It has been proven that these problems are largely identical in their economic essence, and therefore their solution is possible when using a universal toolkit and typical measures that form a sequence of managing the economic stability of an enterprise

Evaluation and Early Warning Simulation of Personnel Unsafe Behavior in Mines Prone to Coal-Rock Dynamic Disasters

At present, aging mines are faced with development bottlenecks such as lack of national policy support, serious problems left over from history, and difficulties in enterprise transformation and development, which seriously restrict the safe production and sustainable development of aging mines. In order to deeply analyze the influencing factors of group unsafe behavior in aging mines, the evolution law of unsafe behavior is qualitatively simulated and quantitatively analyzed to realize the safety evaluation of group unsafe behavior in aging mines. Based on this analysis of the emergence mechanism and influencing factors of unsafe behavior in aging mines, the evaluation index of unsafe behavior in the aging mine population was established. These include six criterion layers and 30 index layers; the mutation level value of the target layer is 0.9405. Group dynamic effect and safety management factors are the two important factors restricting their development and safety. The unsafe behavior of the aging mine groups was evaluated based on game theory and system dynamics—dynamic game simulation on the influence of unsafe behavior in aging coal mines. A qualitative simulation analysis was also performed using the QSIM algorithm. The evolution law of the safety psychology and behavior of aging mine workers are analyzed. This paper shows the importance of the unsafe behavior of aging mines, which helps the safety production and clarifies the safety psychology and the behavior evolution law. This paper puts forward new methods and theories on the safety psychology and behavior evolution law of the safety behavior and provides a reference for the sustainable development of aging mines.

2PnS-EG: A general two-population n-strategy evolutionary game for strategic long-term bidding in a deregulated market under different market clearing mechanisms

Based on assumptions of bounded rationality and limited information, the evolutionary game theory (EGT) can well describe evolution rule of population behaviors and predict individuals’ decision behaviors. Therefore, this paper focuses on a general two-population n-strategy evolutionary game (2PnS-EG), especially for the general two-population three-strategy evolutionary game (2P3S-EG), and applies it to investigate the evolutionary equilibrium properties of long-term strategic bidding issues in deregulated homogeneous and heterogeneous power generation-side markets (PGMs) under different market clearing mechanisms. First, relative net payoff (RNP) parameters are defined for two types of PGMs. Then, based on RNP parameters, the long-term equilibrium characteristics of 2P3S-EG-based homogeneous PGM bidding are investigated in 4 cases based on theoretical analysis and dynamic simulation. Moreover, long-term evolutionarily stable equilibrium characteristics of 2P3S-EG based heterogeneous PGM bidding are investigated via qualitative analysis and dynamic simulation in the conditions of with and without government supervision, which are then further studied via quantitative analysis and dynamic simulation in two clearing mechanisms of MCP and PAB. Results reveal that MCP is more effective than PAB in guiding PGMs to evolve toward an expected and reasonable long-term evolutionarily stable bidding equilibrium state via adjusting the markets’ RNP parameters appropriately. Finally, the future development of EGT-based strategic bidding issues in PGM is discussed. Overall, the models, methods and conclusions of this paper are practicable and scalable to some extent, aiming to enrich research work on long-term bid equilibrium of PGM, and provide some ideas and theoretical reference for relevant departments and PGMs in competitive on-grid bidding with bounded rationality and limited information.

Simulation Analysis of Temperature Effects on the Shear Behavior of Gassy Sand

The gas in gassy sand is enclosed in the pores of soil skeleton mainly in the form of dissolved in water or free gas bubbles, which is considered to be a perfect equilibrium composed of soil particles, pore water, gas, temperature, and overlying pressure. If any of these elements changes, this balance will be destroyed, resulting in disturbance in its mechanical properties. It is generally assumed that the existence of closed gas bubbles will not affect the soil skeleton but increase the compressibility of pore fluid. Assuming that the closed gas bubbles follow Boyle’s law and Henry’s law, the relationship between pore pressure change and volume strain is established. On the basis of the constitutive model which can reflect the temperature characteristics of saturated sand proposed by the author previously, combined with the special characteristics of gassy sand, the effect of temperature effects on the shear behavior of gassy sand is preliminarily explored and analyzed. The results show that under the condition of drained shear, the increase of temperature will increase the shear strength of gassy sand, and the simulation results are in good agreement with the test data. Under the condition of undrained shear, the shear strength of loose gassy sand increases with the increase of temperature, while that of dense gassy sand decreases. Moreover, the larger the gas volume, the more obvious these phenomena tend to be. However, only qualitative simulation analysis is carried out for undrained shear, which needs further verification in combination with relevant tests.

Impact of Decentration and Tilt on Spherical, Aberration Correcting, and Specific Aspherical Intraocular Lenses: An Optical Bench Analysis

Introduction: The human eye is not optically symmetrical, and very few intraocular lens (IOLs) are perfectly centered in the eye. That is why contrast sensitivity can degrade in some conditions, especially in low light. In an optical bench analysis, we compare spherical (A), aberration correcting (B), and specific aspherical lenses (C) in terms of impact of decentration and tilt on the modulation transfer function as well as the simulated overall quality with USAF test targets. Material and Methods: The OptiSpheric IOL PRO2 was used to measure the optical performance of IOLs (A, B, C). In order to assess the optical quality of the IOLs, the optical quality parameters for the aperture size of 3.0 mm and 4.5 mm at the IOL plane were assessed. Through Frequency Modulation Transfer Function (MTF) and Strehl Ratio (SR) values, as well as the “US Airforce 1951 resolution test chart images” as qualitative simulation, were analyzed. All measurements (ISO) were repeated and done for centered, decentered (1 mm), and tilted (5°) IOLs. Results: Centered: The MTF (mean) at 50 lp/mm (IOL A, B, C) with 3.0-mm aperture was 0.794/0.716/0.797 (ISO-1 cornea) and 0.673/0.752/0.723 (ISO-2 cornea) and with 4.5-mm aperture 0.728/0.365/0.751 (ISO 1) and 0.276/0.767/0.505 (ISO 2). The SR (mean) with 3.0-mm aperture was 0.763/0.829/0.898 and with 4.5-mm aperture 0.228/0.386/0.432. Decentered by 1 mm: The MTF (mean) at 50 lp/mm with 3.0-mm aperture was 0.779/0.459/0.726 (ISO 1) and 0.695/0.381/0.662 (ISO 2). The MTF (mean) at 50 lp/mm with 4.5-mm aperture was 0.732/0.348/0.653 (ISO 1) and 0.355/0.069/0.346 (ISO 2). The SR (mean) with 3.0-mm aperture was 0.829/0.543/0.397 and with 4.5-mm aperture was 0.259/0.145/0.192. Tilted by 5°: The MTF (mean) at 50 lp/mm with 3.0-mm aperture was 0.731/0.705/0.751 (ISO 1) and 0.623/0.727/0.732 (ISO 2). The MTF (mean) at 50 lp/mm with 4.5-mm aperture was 0.579/0.406/0.701 (ISO 1) and 0.277/0.512/0.429 (ISO 2). The SR (mean) with 3.0-mm aperture was 0.539/0.478/0.514 and with 4.5-mm aperture was 0.262/0.136/0.201. Conclusion: Aberration correcting IOLs perform best when perfectly centered. The optical performance of aberration correcting IOLs can be markedly downgraded by misalignment. The examined ZO optic performed well in decentration and tilt. The ZO concept seems to be a good alternative to aspheric lenses, as it achieves to combine benefits of spherical and aspheric intraocular lenses. There is no perfect IOL, but fitting and choosing the right one for the individual case seems to be crucial to take advantage of benefits and minimize disadvantages. This is why knowledge of optical properties is also mandatory for the surgeon.

Qualitative simulation of organization quality specific immune decision-making of manufacturing enterprises based on QSIM algorithm simulation

Quality is the core of the enterprise, strengthening organization quality specific immune is the key channel. Organization quality specific immune belongs to science and engineering management field, QSIM qualitative simulation method that refer to computational simulation algorithm is widely used in the science and engineering management field, QSIM qualitative simulation method can solve science and engineering management issues effectively. In this study, qualitative simulation QSIM theory is used to analyze and reason the organization quality specific immune decision of manufacturing enterprises. Combined with the pressure-state-response framework, the management mechanism of organization quality specific immune is analyzed according to state variables, decision variables, system variables and environment variables, and further the qualitative simulation rules for organization quality specific immune decision-making are set according to the causal relationships among variables of organization quality specific immune. This study sets organization quality monitor, organization quality defense and organization quality memory as the decision variables, uses QSIM algorithm for simulating organization quality specific immune decision-making reasoning, compares with the influences of single decision variable and multi-decision variables on organization quality specific immune system through simulation results. Simulation results indicate that QSIM algorithm simulation can be used to simulate and reason organization quality specific immune decision-making in order to help manufacturing enterprises reasonably enhance organization quality specific immune performance and quality performance through three decision variables of organization quality monitor, organization quality defense and organization quality memory. The simulation results will provide new revelation for organization quality specific immune decision-making of manufacturing enterprises.

Detection of Nonradiative Recombination Centers in GaPN by Combining Two‐Wavelength Excited Photoluminescence and Time‐Resolved Photoluminescence

Presence and influence of nonradiative recombination (NRR) centers in an intermediate band (IB)‐type material, GaP1–xNx (), are studied by two‐wavelength excited photoluminescence (TWEPL) method and time‐resolved photoluminescence (TRPL) measurement at 77 K. With the use of below‐gap excitation (BGE) light in addition to an above‐gap excitation (AGE), the PL peak intensity is found to increase which indicates the presence of NRR centers and a secondary excitation from the IB to conduction band (CB). Depending on the effect of different BGE energies, an energy diagram on the distribution of NRR centers and NRR process is interpreted. The saturation of PL increase is attributed to the trap‐filling effect in NRR centers, which allows us to modify the rate equation. The NRR parameters are evaluated by a qualitative simulation of the modified rate equations of one‐level model together with the lifetime determined by TRPL. In continuation of evaluating NRR parameters by rate equation analysis, the addition of TRPL measurement improves accuracy and approaches the determination of NRR parameters. A successful characterization of NRR centers leads to a proper optimization of IB‐type solar cells (IBSCs).

Current density induced growth of Li15Si4 alloy in silicon-carbon anodes during first lithiation process

Li15Si4 alloy growth in silicon-carbon anode materials of lithium ion battery influences the subsequent electrochemical performances, so it's important to investigate Li15Si4 alloy growth during first lithiation process. Yolk-shell nano silicon-carbon particles are assembled with liquid electrolyte in coin-cells under moderate pressure. Li15Si4 alloy is firstly detected at 60 mV (vs Li/Li+) at the current density of 0.1 A g−1, but at 120 mV (vs Li/Li+) at the current density of 1 A g−1 (strictly speaking, Li15Si4 alloy growth at higher voltages cannot be absolutely excluded, but these detections demonstrate the big possibility at the potential), indicating growth potential of Li15Si4 alloy can be higher than 60 mV which was reported in previous literatures. Additionally, Li15Si4 alloy distribution is heterogeneous. The variable potential of Li15Si4 alloy growth is elucidated by TEM characterization and qualitative numerical simulation. The research is benefit for a deep understanding on lithiation behaviors of silicon-based anodes.

Human Health Impact Analysis of Contaminant in IoT-Enabled Water Distributed Networks

This paper aims to assess and analyze the health impact of consuming contaminated drinking water in a water distributed system (WDS). The analysis was based on qualitative simulation performed in two different models named hydraulic and water quality in a WDS. The computation focuses on quantitative analysis for chemically contaminated water impacts by analyzing the dose level in various locations in the water network and the mass of the substance that entered the human body. Several numerical experiments have been applied to evaluate the impact of water pollution on human life. They analyzed the impact on human life according to various factors, including the location of the injected node (pollution occurrence) and the ingested dose level. The results show a significant impact of water contaminant on human life in multiple areas in the water network, and the level of this impact changed from one location to another in WDSs based on several factors such as the location of the pollution occurrence, the contaminant concentration, and the dose level. In order to reduce the impact of this contaminant, water quality sensors have been used and deployed on the water network to help detect this contaminant. The sensors were optimally deployed based on the time-detection of water contamination and the volume of polluted water consumed. Numerical experiments were carried out to compare water pollution’s impact with and without using water quality sensors. The results show that the health impact was reduced by up to 98.37% by using water quality sensors.

Best proximity points of (EP)-operators with qualitative analysis and simulation

In this paper, we analyze a Thakur three-step iterative process adapted for the context of non-self-mappings. Based on this iteration, we state and prove the existence of best proximity points for the recently introduced class of (EP)-non-self-mappings. Under certain assumptions, we study the convergence of the considered Thakur process to a best proximity point for the same class of operators. Moreover, we design a CQ-type algorithm which strongly converges to a best proximity point of such kind of mappings. In addition, we present the CQ-variant of the proposed algorithm that strongly converges to a best proximity pair. Some examples and numerical simulations sustain the efficiency of our new algorithms.

Qualitative Simulation Algorithm for Resource Scheduling in Enterprise Management Cloud Mode

Aiming at the problem of resource scheduling optimization in enterprise management cloud mode, a customizable fuzzy clustering cloud resource scheduling algorithm based on trust sensitivity is proposed. Firstly, on the one hand, a fuzzy clustering method is used to divide cloud resource scheduling into two aspects: cloud user resource scheduling and cloud task resource scheduling. On the other hand, a trust-sensitive mechanism is introduced into cloud task scheduling to prevent malicious node attacks or dishonest recommendation from node providers. At the same time, in the cloud task scheduling, cloud resources are divided according to the comprehensive performance of resources, and the trust sensitivity coefficient of each type of task resources is calculated. Then, according to the trust sensitivity coefficient, the matching cloud tasks are selected for users. Through the comparison of simulation experiments, the customized fuzzy clustering cloud resource scheduling algorithm proposed in this paper reduces the user’s cost of selecting cloud service provider in the cloud resource scheduling. It not only embodies the principle of cloud resource allocation on demand but also can give full play to the advantages of cloud resources and improve the throughput of the whole cloud system and the satisfaction of cloud users.

Qualitative analysis relations

The object of this paper is to introduce relationship models into qualitative analysis to simplify this analysis. The article proposes a set of relations based on the predicate calculus. The concept of “quality relations” is introduced. The relations content is revealed: proportionality, complementarity, connectedness, opposition and dichotomy. Single, double and triple predicates are used. It is shown a qualitative difference between oppositional and dichotomous relations. The principles of qualitative analysis are described. The presence of two directions in the qualitative analysis is shown: social and intellectual. It is shown that qualitative relations are the basis for qualitative analysis and finding cause-and-effect relations. Methods of carrying out qualitative analysis are shown: discrete values, qualitative values, ambiguous values, qualitative process simulation.

Review on fire explosion research of crude oil storage tank

With the rapid development of the world economy, the petrochemical industry energy reserve strategy and production demand increase, petrochemical storage tank farm scale is also expanding, and continue to large, intensive direction of development. In recent years, there are many disastrous accidents such as oil leakage, explosion and combustion of storage tank, so it is necessary to study the combustion and explosion behavior of storage tank. This paper studies the mechanism of explosion combustion in crude oil tank area, summarizes and states the progress of crude oil explosion combustion research at home and abroad, and lists several common risk evaluation methods for tank risk management, which can provide technical support for safety management and accident emergency rescue through qualitative, quantitative evaluation and accident consequence simulation calculation. Therefore, we should sum up the experience and lessons from the accident, strengthen the theoretical research, to avoid the recurrence of similar accidents, and effectively guarantee the safety of national energy reserves.

Performance of SWAT Model in Quantitative and Qualitative Simulation of Runoff and Watershed Protective Measures in Zarrinehrood Basin

Performance of SWAT Model in Quantitative and Qualitative Simulation of Runoff and Watershed Protective Measures in Zarrinehrood Basin