Table of Content

26 November 2022, Volume 41 Issue 6

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The FCM Algorithm based High-order Intuitionistic Fuzzy Time Series Forecasting Model

SONG Min, BAI Yu, LIU Shihu

2022, 41(6):  1-13. 

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A new high-order intuitionistic fuzzy time series forecasting model is proposed in this paper to aiming at the shortcomings of the existing fuzzy time series forecasting models with effective universe of discourse partitioning and fuzzification preprocessing of historical data.The model firstly combines two partitioning methods of equal universe of discourse partitioning and non-equal universe of discourse partitioning based on the FCM algorithm, which better reflects the correlation characteristics of the internal or local patterns of historical data. On this basis, considering the historical data characteristics of intuitionistic fuzzy time series, a more objective method is proposed for intuitionistic fuzzy processing of historical data, which better reflects the fuzzy state of "neither this nor that" of historical data. At the same time, the intuitionistic fuzzy trend approximation factor is used to describe the membership of historical data to fuzzy sets instead of the traditional membership function, then combined with "max-min" aggregation operation, the fuzzy states to be considered are selected reasonably, and the forecasting results are defuzzied. In the experimental part, the model uses the enrollment of students in the University of Alabama and gold futures closing price as the experimental data, and compares the forecasting results with those of some existing models to verify the feasibility and superiority of the new model.

Interval Combination Forecasting Model of Coal Price Based on Improved Weighted Clustering

ZHANG Feng

2022, 41(6):  14-19. 

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Accurate prediction of coal price can improve the scientific sales decision on coal . An interval combination prediction model of coal price based on improved weighted clustering is proposed to improve the accuracy of coal price prediction. This paper analyzes the factors affecting coal production and production from the aspects of coal price and inventory. According to the volatility characteristics of coal price data, the wavelet transform function is defined, and the preprocessing of coal price data is completed by eliminating the noise of coal price data. On the basis of introducing the concept of interval number separation degree in multi-attribute decision-making, the improved weighted clustering method is used to determine the prediction weight of coal price interval combination. By calculating the weighting coefficient of coal price interval combination prediction, the coal price interval combination prediction model is established to realize the prediction of coal price. The simulation results show that the root mean square error and average absolute error can be controlled between 0.1 ~ 0.3 and 0.2 respectively, which greatly improves the prediction accuracy of coal price.

Numerical Solution of Stochastic Differential Equations

LIU Yongcai, BAI Minghua

2022, 41(6):  20-24. 

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Stochastic differential equations are widely used in economy, biology, automation and other fields, but it is often difficult to find their closed solutions. In this paper, Euler method and Milstein method are applied to get the numerical solution of linear stochastic differential equation, and the numerical solutions are compared with closed solution. The accuracy of numerical methods, the relationship between error and step size are analyzed. The numerical results show that the Milstein method is more accurate than Euler method.

Test of Steady-State Fluctuation Theorem on Heat Flux Fluctuation

BI Mingyang, ZHAO Hong

2022, 41(6):  25-31. 

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The research on fluctuation theorem is a topic of general interest in statistical physics, and it is of great importance and practical significance to verify the steady-state fluctuation theorem and investigate the applicable range of the parameters. In this article, we study three kinds of typical one-dimensional lattices models coupled with Langevin heat reservoirs at different temperature on both ends to carefully verify the steady-state fluctuation theorem. Numerical results show that all of the heat flux of three kinds of models strictly obey the steady-state fluctuation theorem when in the limit that the measure time window goes to infinity. The deviation of fluctuation theorem rising with the increase of the system size under the case of finite measure time window is found as well. There is a scaling change on different size of systems which can be good to rescale into a universal dependency. The nonlinear deviation of the fluctuation relation is also studied in this article.

Application of Fluorescent Optical Fiber Temperature Technology to Photovoltaic Cell Components

ZHU Qixiang

2022, 41(6):  32-37. 

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In this paper, the temperature measurement probe is directly installed on the hot spot on the surface of the photovoltaic cell by combining the fluorescent optical fiber temperature measurement technology and the feedforward control method and more energy is obtained on the surface area. The "application bottleneck" that the hot spot temperature on the surface of the solar photovoltaic cell module is difficult to directly measure is solved and the power generation efficiency of the photovoltaic cell module module is improved as well.

Research on Internet Information Security Technology Based on SDSoC Hash Function Improvement

XU Caifang

2022, 41(6):  38-42. 

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Uses SDSoC technology to improve the traditional hash function (Hash Function) algorithm, and proposes an information encryption algorithm optimization model based on SDSoC technology. Algorithms are compared as well. The results show that the throughput of the hash function algorithm based on traditional hardware is lower, while the throughput of the AES algorithm based on SDSoC is higher; when the clock cycle is ap_clk, the target running time is Target, the evaluation running time is Estimated, and the error range time is Uncertainty , the running time of the traditional hash function algorithm is roughly in the range of 8.17±1.26, while the running time of the SDSoC-based AES algorithm is in the range of 8.11±1.20, and the execution speed of the improved algorithm is greatly improved. Therefore, the resource utilization rate of the improved algorithm is significantly lower than that of the traditional algorithm, which can improve the performance of the algorithm well, and the overall performance is higher.

Research on Application of Quantum Particle Swarm Optimization Algorithm to Mobile Robot Path Planning

YANG Jing

2022, 41(6):  43-48. 

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A mobile robot path planning method based on Quantum particle swarm optimization (QPSO) algorithm is proposed to solve the problem of optimizing the blind search of mobile robots in the solution space, by improving the particle swarm algorithm. Optimizing the convergence speed and population dispersion of individual particles in the particle swarm to complete the dynamic adjustment of the inertia weight to solve the shortcomings of the traditional particle swarm algorithm of premature convergence can make the weight of the QPSO algorithm controllable and adaptive sex. At the same time, the natural selection method is used to update the position of the particle swarm, increasing the diversity of the particle swarm's motion path, and greatly improving the global search ability and convergence speed of the particle swarm. Finally, through the analysis of path planning software simulation and experimental test results, it can be seen that the algorithm is better than the PSO algorithm in the global search ability and convergence speed in the path planning of mobile robots.Among them, the average cost is reduced by about 0.2m and the average time consumption is reduced by 1.28s. This verifies the effectiveness and feasibility of the proposed algorithm.

Research on Intelligent Recommendation Evaluation of Test Questions Based on Collaborative Filtering Algorithm

HU Wei, WANG Zilan

2022, 41(6):  49-54. 

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With the rapid development of smart education and digital teaching, how to quickly and accurately understand students' mastery of knowledge points has become a problem to be solved for intelligent teaching. The research uses the improved collaborative filtering algorithm to construct an intelligent recommendation evaluation model for test questions, realizes the intelligent recommendation of students' test questions and automatic evaluation of answering results, and conducts application experiments on the intelligent recommendation model. The experimental results show that the highest hit rate of the improved collaborative filtering algorithm is 89%, and the average hit rate is 15.6%. Compared with the traditional filtering algorithm, its hit rate is increased by 5.4%. In the practical application test, the model can quickly obtain the results and scores, and according to the students' scores and errors, it can provide students with targeted questions and learning suggestions. The recommendation effect of the improved collaborative filtering recommendation algorithm is higher than that of the traditional algorithm, which can effectively increase teachers' understanding of students' knowledge, reduce teachers' workload, and help teachers improve teaching quality.

Spatio-temporal Change of Land Use in Kunming Based on Remote Sensing

LIU Fenglian, YANG Lei

2022, 41(6):  55-62. 

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The spatial-temporal change characteristics of land use in Kunming were analyzed based on data obtained from RS and GIS technology and remote sensing images Kunming from 2000—2020. The research found that: from 2000 to 2020, the land use types in Kunming are mainly woodland, grassland and cultivated land with the area of cultivated land, woodland and grassland decreasing continuously, while the area of construction land increasing significantly; in 2015—2020 and 2005—2010, the rate of land use change was relatively rapid, and construction land changed fastest among all land types; cultivated land, woodland, grassland and construction land have a large area of mutual transfer, of which cultivated land is converted to construction land the most.

Spatio-temporal Distribution Characteristics and Influencing Factors of Hiking Tourism in Yunnan Based on GPS Data

ZHAO Ouyi, YIN Yifan, WANG Jiaxue

2022, 41(6):  63-72. 

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The temporal and spatial distribution and influencing factors of hiking tourism in Yunnan were analyzed by using the method of seasonal intensity index, kernel density analysis, local autocorrelation method and buffer analysis Based on GPS data of the hiking tracks based on GPS data of the hiking tracks. The results were as follows: (1) In terms of inter-annual variation, the hiking tourism in Yunnan showed obvious characteristics of growth stages; in the field of the changes during the year, Yunnan hiking tourism was seasonal, concentrated in spring and early summer. (2) The spatial distribution of hiking track had migrated from northwest to southeast with the distribution range expanding and the degree of aggregation decreasing continuously, and it had experienced "polar core" distribution-"point axis" spatial distribution-"core-edge" structure. The correlation pattern of the local area of the hiking track node showed obvious geographical differentiation characteristics, forming a spatial pattern of decreasing heat from east to west. (3) The hiking tracks were mainly distributed along lakes and rivers where there were high vegetation coverage with the altitude between 1500m and 2500m. The distribution of hiking tracks was affected by factors such as altitude, vegetation, rivers, cities, scenic spots, economy and population.

Spatial and Temporal Changes of Cultivated Land Use Efficiency and Its Influencing Factors in Yunnan from 2009 to 2019

TONG Shaoyu, ZHOU Xinyu

2022, 41(6):  73-83. 

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Cultivated land is an important material basis and the most basic means of production for human survival and social development. The rational development and utilization of cultivated land is very important for stabilizing food production, ensuring effective food supply, and promoting rural economic and social stability. This paper first estimates the cultivated land use efficiency of Yunnan and its 16 areas from 2009 to 2019 by using the data envelopment analysis method, then analyzes its temporal and spatial change characteristics, and finally studies the influencing factors of cultivated land use efficiency by using Tobit model. The results show that the comprehensive efficiency of cultivated land use in Yunnan was not at effective level and a downward trend from 2009 to 2019; the comprehensive efficiency of cultivated land use in Yunnan among them; the change of comprehensive efficiency and scale efficiency in a similar downward trend, while the change of pure technical efficiency being relatively small and effective in most years. The cultivated land use efficiency and its changing trend of 16 areas in Yunnan are different, which can be roughly divided into four types: stable effective state type, continuous increase to effective state type, continuous decline to ineffective state type and fluctuation type. The utilization efficiency of cultivated land in 8 areas had reached an effective level. Most of them were traditional agricultural main producing areas with good agricultural production conditions in Yunnan (except Nujiang Prefecture), and were also heavily influenced by various preferential policies of the state. Except Yuxi City, they were mainly distributed in the marginal areas of Yunnan. In terms of the spatial pattern change of cultivated land use efficiency, there were many areas with high value of cultivated land use efficiency in Yunnan in 2009,which were distributed contiguously, mainly in the east and west sides of Yunnan. By 2019,there were few high-value areas in the central region in Yunnan, and the high value area decreased, and the distribution area contracted to the marginal areas of Yunnan. From the perspective of the influencing factors of cultivated land use efficiency, per capita GDP agricultural development level, three main agricultural product output factors have positive effects on cultivated land use efficiency, while fertilizer input and rural per capita disposable income have negative effects on cultivated land use efficiency.

An Empirical Analysis of the Theoretical Expansion of Investment Multiplier

GAO Xingyou, CHEN Yu

2022, 41(6):  84-90. 

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An extended investment multiplier formula was put forward in the paper “An Extensive Study of Factors Affecting the Investment Multiplier”, which regarded investment as a function of income, thus introducing marginal propensity of investment into the formula, which made the formula more reasonable in theory. However, there is no empirical test whether investment can be regarded as a linear function of income and whether this formula is reasonable in practice. From the three dimensions of literature evidence, mechanism analysis and empirical test, it is proved that investment is a linear function of income. Based on marginal analysis and regression analysis, this paper makes an empirical analysis using the data of consumption, taxation, import, investment and income in China in the past 40 years, and compares the results of theoretical expansion with those of traditional theories. The research shows that, first, the multiplier obtained by the expansion of the theory is larger than that of the traditional theory; second, if the marginal analysis method is chosen, some abnormal data may appear in the formula of theoretical expansion, but if the method of regression analysis is chosen, the results are reasonable.

Identification and Optimization of Uncoordinated Coupling of Ecology-Urbanization-Tourism Based on Gray System Theory: A Case Study of Chongqing

YANG Guangming, YANG Yunrui, GUI Qingqing

2022, 41(6):  91-101. 

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[Objective] The development of each system of ecological environment, urbanization and tourism is crucial to the coordinated and sustainable socioeconomic development, and it is important to clarify the relationship and current situation among the three systems for the future development of Chongqing city. [Methods] Based on the gray system theory, the ecological environment, urbanization and tourism systems in Chongqing were studied from the perspective of non-coordinated coupling. The coordinated development of ecological environment, urbanization and tourism in Chongqing was explored by constructing gray correlation model and non-coordinated coupling model. [Results] ① The correlation degree of each indicator within the system of ecological environment, urbanization and tourism is above 0.5, with each indicator having a strong influence on the development of ecological environment, urbanization and tourism. The inter-system correlations are all above 0.65, which are at high or very high correlation levels, with the systems being closely linked and influence each other. ② The ecological environment, urbanization and tourism development levels all show an overall increase during 2000-2019, but the ecological environment is influenced by tourism and urbanization, showing large fluctuations. ③ The non-coordinated coupling degree of ecological environment, urbanization and tourism decreased from 0.7304 in 2000 to 0.0751 in 2019, and the non-coordinated coupling degree is gradually weakening, and the level of coordinated development among systems is getting better. [Conclusion] The relationship between the three systems of ecological environment, urbanization and tourism in Chongqing is close and the level of non-coordination is low. In the process of future urbanization and tourism development, more attention should be paid to ecological environment restoration to achieve coordinated and sustainable development among the systems.

Impact of Local Government Intervention on Upgrading of Industry and Improvement of Environmental Quality Based on the Western Provincial Panel Data Model

SUN Liping, YANG Jun

2022, 41(6):  102-107. 

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This paper takes the panel data of 12 provinces (cities) in the western region from 2000 to 2020 as the research object, empirically analyzes the impact of local government on industrial transformation and upgrading and environmental quality improvement. In order to avoid endogeneity, the total area of the region and the number of county-level administrative divisions in each province are selected as instrumental variables, the instrumental variable model is used to estimate, and the result is robust.The results are stable in considering variables and samples and show that: first, the total effect of local government intervention is net income, the stronger the government intervention, and the net income is greater; second, the government intervention has a positive role in promoting industrial upgrading and environmental quality improvement; third, government intervention has different effects , and the stronger the intervention, the more significant the improvement of environmental quality will be, but the less significant the effect on the upgrading of industrial structure.

Empirical Study of Population Agglomeration, Industrial Structure Upgrade and Economic Growth in Yunnan

DAI Yujie, XIONG Yunbiao

2022, 41(6):  108-114. 

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This paper builds a PVAR model based on the panel data of cities and counties in Yunnan Province from 1999 to 2019 to systematically analyze the interaction between population agglomeration, industrial structure upgrading and economic growth. The results show that there is a dynamic relationship between population agglomeration and economic growth, and population agglomeration has a small inhibitory effect on the upgrading of industrial structure; there is a dynamic relationship of mutual inhibition between industrial structure upgrading and economic growth; and the impact of economic growth on industrial structure upgrading is "inverted U-shaped". Accordingly, suggestions for adapting to the trend of population agglomeration and optimizing the industrial structure to support high-quality economic development are put forward.

Infiltrating Ecological Civilization Thought into Curriculum-based Ideological and Political Education at Application-oriented Universities: A Case Study of Plant Physiology and Biochemistry

GUO Lihong, LI Zhumei, NING Tiao

2022, 41(6):  115-122. 

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Ecological civilization thought is the fundamental observance and important guarantee for realizing the modernization of harmonious coexistence between man and nature. Ecological civilization thought is infiltrated into the curriculum of application-oriented universities, which is an important channel for enhancing students' values of ecological civilization. In this paper, the core elements of ecological civilization thought is explained on the basis of analyzing the necessity by infiltrating ecological civilization thought into the curriculum in application-oriented universities. Plant Physiology and Biochemistry is major taken as an example. The ideological elements of ecological civilization values are fully excavated. The teaching cases of the course which are infiltrated by ecological civilization thought are designed from eight dimensions. Ecological civilization thought education is organically combined with professional knowledge teaching, which will be useful for cultivating students to establish correct ecological civilization values.

A Case Study of Differences of Mathematics Learning between Students of Ethnic Groups and People of Han at Junior Middle School in Yunnan

LIU Jun, ZHU Chunyan, LUO Hongying, YAN Jingmei, ZHANG Fangrong

2022, 41(6):  123-128. 

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Differences in mathematics learning between students of ethnic groups and students of Han the same class in a junior middle school in Yunnan are studied based on data collected through questionnaire, academic quality survey, interview and other methods from dimensions of learning psychology, learning methods and learning results for three consecutive years. The results show that students of ethnic groups have low self-confidence, weak motivation, low pressure and low performance in mathematics learning. The main reason for this is the students' psychological maturity and stereotyped effect. Therefore, we should attach great importance to the differences in mathematics learning between students of ethnic groups and students of Han students in junior middle schools.