Comprehensive Weight Research Articles

A new method for evaluating the firing precision of multiple launch rocket system based on Bayesian theory

How to effectively evaluate the firing precision of weapon equipment at low cost is one of the core contents of improving the test level of weapon system. A new method to evaluate the firing precision of the MLRS considering the credibility of simulation system based on Bayesian theory is proposed in this paper. First of all, a comprehensive index system for the credibility of the simulation system of the firing precision of the MLRS is constructed combined with the group analytic hierarchy process. A modified method for determining the comprehensive weight of the index is established to improve the rationality of the index weight coefficients. The Bayesian posterior estimation formula of firing precision considering prior information is derived in the form of mixed prior distribution, and the rationality of prior information used in estimation model is discussed quantitatively. With the simulation tests, the different evaluation methods are compared to validate the effectiveness of the proposed method. Finally, the experimental results show that the effectiveness of estimation method for firing precision is improved by more than 25%.

A mimic fusion method based on difference feature association falling shadow for infrared and visible video

Optimal selection of fusion strategy based on image difference information is an important way to improve the adaptive performance of infrared photoelectric detection systems. Heterogeneous difference feature amplitudes often have different dimensions and orders of magnitude, so the traditional fusion model cannot adjust the fusion algorithm effectively according to the difference feature attribute value, resulting in poor fusion effect or even fusion failure. Furthermore, the existing fusion methods often ignore the association between the different feature information, which leads to problems such as weak semantic interpretation of the fusion process and difficulty in improving the fusion effect. As a result, we draw on the multi-mimetic idea of mimic octopus, and propose a mimic fusion method based on difference feature association falling shadows for infrared and visible video. Firstly, we select six difference features to quantitatively describe the amplitudes of three types of significant complementary information in bimodal video. Secondly, the difference feature frequency distribution is obtained by KNNE. Thirdly, construct the difference feature comprehensive weight to coordinate the relationship between the multiple attributes of difference feature, so as to determine the main difference feature of each frame according to the result. Then use PCCs to calculate the correlation between the any two difference features comprehensive weights to obtain the feature association matrix. Finally, the association synthesis rules of the heterogeneous difference feature fusion validity are established, and the mimic algorithm variables are optimized and selected according to the association falling shadow results to realize the mimic fusion for infrared and visible video. The experimental results show that the method in this paper has achieved remarkable results in preserving the typical infrared target and visible light structural details in the whole video, and is significantly better than other single fusion methods in quantitative analysis and qualitative evaluation.

Online learning resource recommendation method based on multi-similarity metric optimization under the COVID-19 epidemic

With the continuous COVID-19 pneumonia epidemic, online learning has become a normal choice for many learners. However, the problems of information overload and knowledge maze have been aggravated in the process of online learning. A learning resource recommendation method based on multi similarity measure optimization is proposed in this paper. We optimize the user score similarity by introducing information entropy, and use particle swarm optimization algorithm to determine the comprehensive similarity weight, and determine the nearest neighbor user with both score similarity and interest similarity through secondary screening in this method. The ultimate goal is to improve the accuracy of recommendation results, and help learners learn more effectively. We conduct experiments on public data sets. The experimental results show that the algorithm in this paper can significantly improve the recommendation accuracy on the basis of maintaining a stable recommendation coverage.

Probabilistic double hierarchy linguistic Maclaurin symmetric mean-MultiCriteria Border Approximation area Comparison method for multi-criteria group decision making and its application in a selection of traditional Chinese medicine prescriptions

Traditional Chinese medicine (TCM) has gradually played an indispensable role in people’s health maintenance, especially in the treatment of chronic diseases. However, there is always uncertainty and hesitation in the judgment and understanding of diseases by doctors, which affects the status recognition and optimal diagnosis and treatment decision-making of patients. In order to overcome the above problems, we lead into probabilistic double hierarchy linguistic term set (PDHLTS) to accurately describe language information in traditional Chinese medicine and make decisions. In this paper, a multi-criteria group decision making (MCGDM) model is constructed based on the MSM-MCBAC (Maclaurin symmetric mean-MultiCriteria Border Approximation area Comparison) method in the PDHL environment. Firstly, a PDHL weighted Maclaurin symmetric mean (PDHLWMSM) operator is proposed to aggregate the evaluation matrices of multiple experts. Then, combined with the BWM and maximizing deviation method, a comprehensive weight determination method is put forward to calculate the weights of criteria. Furthermore, we propose PDHL MSM-MCBAC method based on the Multi-Attributive Border Approximation area Comparison (MABAC) method and the PDHLWMSM operator. Finally, an example of a selection of TCM prescriptions is used and some comparative analyses are made to verify the effectiveness and superiority of this paper.

Research on the Evaluation and Spatial Difference of China's Regional Logistics Digital Innovation Ability Based on Entropy Weight — Toptsis

With the transformation of economic development and the innovation and promotion of high-tech, the logistics industry is also entering an important stage of transformation and upgrading. With the progress of science and technology, the traditional logistics industry is bound to transform to the direction of digital logistics. In this process, the digital innovation ability of logistics is the key to transformation and upgrading. After combing the relevant research, this paper constructs the evaluation index system of logistics digital innovation ability, uses entropy weight method to calculate the comprehensive weight of each index, and uses TOPSIS method to calculate the score, analyzes the index panel data of 30 provinces and cities in China from 2016 to 2020, and compares the four plates in space According to the logistics digital innovation ability of the eight special economic zones, this paper analyzes the spatial differences of China's logistics digital innovation ability, and puts forward the existing problems and future prospects.

Tuning Polymer Molecular Weight Distribution in Cationic RAFT Polymerization by Mixing Chain Transfer Agents†

Comprehensive SummaryPolymer dispersity (Đ) or molecular weight distribution (MWD) is a basic but vital parameter for the properties of polymeric materials. Developing new methodologies for controlling polymer MWD is emerging as a research hotspot. However, the methods to tune polymer MWD in cationic polymerization are still not well explored. Herein, we present a simple method to control the dispersity of poly(isobutyl vinyl ether) (PIBVE) by mixing two different chain transfer agents in batch visible light induced cationic RAFT polymerization. A broad dispersity range (Đ ≈ 1.16—1.80) was successfully achieved while maintaining monomodal MWD. Moreover, chain extension of PIBVE through both cationic polymerization and radical polymerization has been studied, which also provides a method to tune polymer MWD in mechanism transformation polymerization.

Dynamic assessment and system dynamics simulation of safety risk in whole life cycle of coal mine.

Based on the accident causation theory, the mechanism and inducement of construction safety risk in mining enterprises are clarified. The safety risk system of mining enterprises is divided into five subsystems: personnel, material equipment, technology, environment, and management by rough set theory. The comprehensive weight of each risk factor is calculated by network analytic hierarchy process and fuzzy comprehensive evaluation method. Taking a mine in Shanxi Province as the research object, the causal traceability diagram and stock flow diagram of the risk system of mining enterprises are constructed by means of system dynamics model. The influence of various risk factors of the mine on the overall safety risk management level of the enterprise is simulated, and the numerical value of key personnel influence factors is adjusted. The sensitivity changes of safety productivity and safety risk management level of mining enterprises in different situations are analyzed. The results show that: (1) the management and personnel subsystem has the greatest impact on the safety risk management of mining enterprises, followed by the technology, material equipment, and environment subsystem. (2) Increasing safety input can improve the safety level and reduce the expected safety value time, otherwise it will reduce the safety level and delay the expected safety value time. (3) Further simulation of the personnel subsystem, it is found that the factors affecting the safety level of mining enterprises contain six factors, namely, the technical level of construction personnel, the management level of manager, the conduct code of construction personnel, the safety consciousness of practitioners, the basic quality of construction personnel, and the physical and mental state of construction personnel. (4) The conversion rate of personnel safety input to manager's management level and the safety consciousness of practitioners presents a steep decline-slow rise-gradually steady development trend, which mainly because the benefits of safety input have certain time delay and lag.

Risk Assessment of Water and Sand Inrush in Mining under Thick Loose Layer Based on Comprehensive Weight-Cloud Model

Many deep mining mines in southwestern Shandong Province of China are covered with thick loose layers. When mining near the loose layers, there is a risk of water and sand inrush, which threatens the personal safety of miners. The prediction of sudden water and sand inrush is difficult due to the comprehensive influence of many factors, and the influencing factors are fuzzy and random. To solve this problem, in this paper, a new risk assessment method of water and sand inrush based on comprehensive weight and cloud model was proposed. Seven factors are selected as indexes: the aquifer thickness, the thickness ratio of sand layer to clay layer, the thickness of bottom clay layer, the coal seam thickness, the percentage of core recovery, the geological structure, and the bedrock thickness. The assessment index system is established, and the index is divided into three grades. A comprehensive weighting method, which combines analytic hierarchy process (AHP), entropy weight method (EWM), and minimum entropy principle, is used to reasonably assign the weight of index. Based on the cloud generator equation, the membership function is obtained. The assessment result of the assessment object is obtained by combining the membership degree and the weight of index. The comprehensive weight-cloud model assessment method is applied to the risk assessment of water and sand inrush in the 6311-2 working face in the sixth mining area of Baodian Coal Mine. According to the assessment results, the following conclusions can be drawn: (1) the bedrock thickness and the coal seam thickness are the main factors of water and sand inrush under loose layer mining; (2) the assessment results obtained by the comprehensive weight-cloud model method are consistent with the actual situation. The assessment method can provide scientific reference for the safe mining under the thick loose layer in the deep mines of southwest Shandong.

Optimisation analysis of distribution network planning based on the IVIF-AHP method

Abstract Distribution network planning is an important task in the process of power grid construction and development. Scientific and rational planning is the key factor for the economic construction and reliable operation of the power grid. Aiming at the difficulty in quantifying the weight of distribution network planning schemes, a comprehensive evaluation method of distribution network planning schemes based on the interval-valued intuitionistic fuzzy analytic hierarchy process method is proposed. First, a comprehensive evaluation index system is established from the four aspects of power supply, namely reliability, economy, power supply quality and safety of the distribution network. Then, a comprehensive evaluation method of electricity reliability optimised by entropy weight method is adopted by analytic hierarchy process, which considers both subjective situation and objective weighting. At the same time, the comprehensive weight of the aggregation of the criterion layer and the scheme layer is calculated. Finally, the link between the aggregation matrix and the index weights of the criterion layer is used to calculate the weights of the scheme layer so that they can be sorted out. The experimental results show that the effectiveness and feasibility of the planning and analysis indicators and evaluation methods of the method proposed in this paper are verified by a numerical example.

Evaluation of the Development Potential of Urban Underground Space Using Set Pair Analysis and the Comprehensive Weight Method

Recently, a series of urban diseases have seriously impacted the development of large and medium cities. The development of urban underground space (UUS) is widely regarded as an effective solution. Due to the irreversibility of underground space resources, it is important to formulate scientific and reasonable development planning based on evaluation of the development potential of urban underground space (DPUUS). In this work, from the perspective of society, economy, and environment, an evaluation model of the DPUUS was established, and nine indexes were selected, including population density, vehicle possessive quantity per 100 capita, policy support, GDP per capita, GDP per km2, land price, geographical position, geological conditions, and natural disasters. The comprehensive weight method (CWM) combined with subjective and objective weights was used to determine the final weight of the evaluation index. Set pair analysis (SPA) and the credible degree recognition criterion (CDRC) were applied to determine the DPUUS grade of each city, which can provide a new idea for DPUUS.

Evaluation and prediction of ecological carrying capacity in the Qilian Mountain National Park, China

With increasing human impacts on the ecosystem in natural protected areas, there is an urgent need to undertake an assessment of ecological carrying capacity taken as a benchmark for assessing regional sustainability. Based on satellite remote sensing and socio-economic statistical data from 2000 to 2019, this study distinguished the controlling factors for the spatial and temporal patterns of ecological carrying capacity in the Qilian Mountain National Park, one of the 10 pilot national parks in China. The ecological carrying capacity index (ECCI) was developed by using the Driver-Pressure-State-Impact-Response framework and a comprehensive weight method. The results showed that the multiyear averaged ECCI was low in the south and west but was high in central and eastern regions. The spatial distribution of the ECCI was constrained by soil resources, ecosystem quality, land use/cover and water environment. At the regional scale, the ECCI decreased from 2000 to 2014, especially in Tianzhu, where farmland expansion and severe droughts reduced habitat quality and ecosystem function. However, the ECCI increased significantly from 2014 to 2019, which was attributed to a warm moist climate and the implementation of eco-environmental protection policies. Forest and grassland coverage, soil and water conservation, waste water treatment amount and terrestrial water reserves accounted for 35%, 26%, 20% and 8%, respectively, of the temporal variability in the ECCI. Concurrent with national park development, the ECCI is predicted to increase in most areas from 2020 to 2029 by back-propagation artificial neural networks, except for Sunan, Shandan and Menyuan, possibly owing to increasing conflicts between humans and the environment. The findings of this study provide evidence about the effectiveness of government policies in promoting regional sustainability by altering ecosystem composition and function. In addition, the dominant drivers for the temporal variability of ecological carrying capacity varied in space according to stepwise regression analysis, calling for region-specific management strategies in mountain protected areas and their surroundings.

Real-Time Monitoring and Control of the Breakthrough Stage in Ultrafast Laser Drilling Based on Sequential Three-Way Decision

Real-time monitoring and control of breakthrough stage are essential issues in ultrafast laser drilling (ULD) process. This paper proposed a novel intelligent methodology to address the decision bias problem in monitoring and control of breakthrough stage. Eight time-domain statistical features were extracted after analyzing the correlation between the optical emission signal and the drilling process and data processing. To build the identification model of breakthrough stage, support vector machine (SVM) method was adopted and the identification accuracy can up to 98.42%. Even so, there is a large deviation between the prediction breakthrough time by the identification model and the actual breakthrough time, which can up to 3.81s. Considering the decision bias, the comprehensive Gaussian weight sequential three-way decision (CGW-S3WD) method was proposed for the first time. Compared to the actual breakthrough time, the mean decision time is only delayed by 0.375s based on the combination of the identification model and CGW-S3WD method under simulated conditions. Finally, the method was applied to monitoring and control of breakthrough stage in the actual ULD process. Experimental results demonstrate that the control delay time is only 0.354s and the high-quality holes and protection of the back wall can be achieved simultaneously. The research confirms that the method can reduce the decision bias and provides a new perspective for accurate monitoring of complex industrial scenarios.

Overall Resilient Evaluation of Surrounding Rock of In-Service High-Speed Railway Tunnel Based on Information Fusion-Improved Fuzzy Matter-Element

Once the high-speed railway tunnel is put into use, its resilience will determine the possibility of permanent safety of the tunnel due to the closure of the structural space of the high-speed railway tunnel in service. Resilience theory is introduced into a risk analysis of operating high-speed rail tunnels to improve the ability to respond to risks in operating high-speed rail tunnels and to relieve the aging phenomenon caused by changes in the tunnel with time. First, an evaluation framework for the safety resilience of existing high-speed railway tunnels is constructed. Starting from the attributes of resilience such as resistance, adaptability, and resilience, and considering the characteristics of high-speed railway tunnels, protective measures, emergency management measures, and other factors, we fit the risk factors and probability of accident type of the high-speed railway tunnel and establish a tunnel safety resilience evaluation index system with 10 indexes. Secondly, the method of information fusion is used to combine subjective weighting and objective weighting. Then, the comprehensive weight of the evaluation index is obtained based on the principle of minimum discriminant information. Thirdly, the system resilience evaluation model based on the TOPSIS improved fuzzy matter-element is constructed to determine the classification criteria of resilience. On this basis, based on the temporal and spatial variability of the ductile tunnel, the concepts of ductile transition and ductile attenuation are introduced and the tunnel toughness optimization model is established to suppress the attenuation situation, enhance the transition ability, and then improve the system resilience level. On this basis, an optimal lifting scheme is obtained. Finally, taking Ai-Min tunnel of Ha-Mu high-speed railway as the engineering background, the flexibility of the resilience system is calculated, and the resilience grade (3) of the rock system surrounding the tunnel is obtained. Combined with the numerical model, improvement measures for specific tunnel facilities are proposed. The results show that the Ai-Min tunnel system has a general ability to resist external intrusion and prevent disasters, and the resilience level is general. It should focus on improving the resilience level of the transition index. The resilience evaluation results of the evaluation model are consistent with the actual situation of the project.

Comprehensive evaluation of corroded grounding electrodes considering the impulse characteristics

The grounding electrodes are buried in a harsh soil environment, which will cause corrosion. Corroded grounding electrodes directly affect the safe and stable operation of the power system. Therefore, it is particularly important to detect the corrosion degree of the grounding electrodes accurately. The existing methods have the following problems: 1) Power-frequency grounding resistance is used as a single criterion, and lack of considering the impulse characteristics, which is difficult to accurately judge the corrosion degree and could cause a potential safety hazard. 2) Lacking considering the environmental PH value, water content, salt content, and other factors of the buried soil, which is easy to lead to misjudgment of corrosion degree. To solve the problems, this paper studies a comprehensive evaluation of corroded grounding electrodes considering impulse characteristics. Based on thermal stability, impulse characteristics, and power frequency characteristics, the minimum safety diameter of grounding electrodes and the factors that affect the corrosion of the soil environment are studied. According to the relationship between each evaluation factors and corrosivity, the membership is calculated and combined with the comprehensive weight determined by the sum of the squares of deviation. The fuzzy evaluation method is adopted to obtain the corrosive evaluation matrix Y, and the corrosive index C is proposed to quantify the corrosive strength. Combined with the minimum safety diameter, the residual life range of the grounding electrodes is predicted and the corrosion degree is divided. Finally, a comprehensive corrosion evaluation algorithm considering impulse characteristics is proposed. The results show that this method not only considers the soil environmental factors but also considers the grounding characteristics of the grounding electrodes, especially the impulse characteristics. This method is more comprehensive than other evaluation methods which only consider the soil environment and can realize trenchless corrosion detection of grounding electrodes. Therefore, the contribution of this work is of great significance to the operation and maintenance of tower grounding electrodes.

Underfrequency Load Shedding Scheme for Islanded Microgrids Considering Objective and Subjective Weight of Loads

With the rapid development of microgrids, the types of users and loads in microgrids are increasing. Comprehensively reflecting the value of loads in load shedding decisions is one of the main challenges for the intelligent control of an islanded microgrid. However, the existing load shedding schemes ignore the user’s subjective preference for multiple attributes of loads, which are insufficient for reflecting the comprehensive value of loads. To address the aforementioned problem, an underfrequency load shedding (UFLS) scheme based on the comprehensive weight of loads is proposed. This scheme evaluates the multiple attributes of loads and the user’s preference for load attributes based on the entropy method with high adaptability (EMHA) and the analytical hierarchy process (AHP) to obtain the objective and subjective weights of loads. Then, the comprehensive weight of loads is calculated based on the relative entropy to determine the sequence of load shedding. Furthermore, the optimal objective function of the comprehensive cost of load shedding is constructed, and gray wolf optimization (GWO) is used to solve the objective function and obtain the optimal load shedding scheme. Ultimately, the effectiveness of the proposed scheme is verified based on a modified standard IEEE 37-bus system.

Effects of the healthy lifestyle community program (cohort 1) on stress-eating and weight change after 8 weeks: a controlled study

Stress-eating (eating more or more unhealthily in order to accommodate to stress), contributes to the development and maintenance of obesity. The effect of comprehensive weight loss interventions on changes in stress-eating as well as the contributing role of stress-eating on weight reduction has not been examined. The impact of the 8-week intensive phase of the Healthy Lifestyle Community Programme (HLCP, cohort 1) on emotional, external and restrained eating, as expressions of stress-eating was evaluated in a non-randomized controlled trial. Intervention: 14 seminars (twice per week, including practical units), complemented by stress-regulation and cooking workshops and coaching sessions empowering participants to change their behaviour towards a healthy plant-based diet (ad libitum), stress regulation, regular exercise and to focus on social support. Participants were recruited from the general population. In the intervention group, 91 participants (IG; age: 56 ± 10, 77% female) and in the control group, 52 (CG; age: 62 ± 14, 57% female) were enrolled. At baseline, participants of the IG reported higher levels of stress (9.7 ± 5.4 points [P] vs. 7.6 ± 6.2; p < 0.011), and of emotional eating (27.9 ± 9.4 vs. 20.0 ± 7.1; p < 0.001) and external eating (29.1 ± 4.9 vs. 25.5 ± 5.6; p < 0.001) than participants of the CG. Within 8 weeks, in the IG, scores of emotional eating (− 3.5 ± 5.4 P) and external eating significantly decreased (= − 2.0 ± 3.8 P), while restrained eating increased (2.7 ± 5.0 P; p for all < 0.001). Weight change was negatively correlated with change of external eating (R2 = 0.045; CC = − 0.285; p = 0.014), indicating that a greater weight change was associated with a smaller change of external eating. This is the first study to prospectively investigate the role of stress-eating on the weight reduction effect of comprehensive lifestyle interventions. Our data confirm that overweight is associated with EE and external eating and suggest that the HLCP is capable to reduce both, weight and stress-eating.Trial registration: German Clinical Trials Register (DRKS; reference: DRKS00018821; September 18th 2019; retrospectively registered).

In it for the long haul: the complexities of managing overweight in family practice: qualitative thematic analysis from the Health eLiteracy for Prevention in General Practice (HeLP-GP) trial

BackgroundAustralia has one of the highest rates of overweight and obesity in the developed world, and this increasing prevalence and associated chronic disease morbidity reinforces the importance of understanding the attitudes, views, and experiences of patients and health providers towards weight management interventions and programs. The purpose of this study was to investigate patients, family practitioners and family practice nurses’ perceptions and views regarding the receipt or delivery of weight management within the context of the HeLP-GP intervention.MethodsA nested qualitative study design including semi-structured interviews with family practitioners (n = 8), family practice nurses (n = 4), and patients (n = 25) attending family practices in New South Wales (n = 2) and South Australia (n = 2). The patient interviews sought specific feedback about each aspect of the intervention and the provider interviews sought to elicit their understanding and opinions of the strategies underpinning the intervention as well as general perceptions about providing weight management to their patients. Interviews were recorded and transcribed verbatim, and coding and management conducted using NVivo 12 Pro. We analysed the interview data using thematic analysis.ResultsOur study identified three key themes: long-term trusting and supportive relationships (being ‘in it for the long haul’); initiating conversations and understanding motivations; and ensuring access to multi-modal weight management options that acknowledge differing levels of health literacy. The three themes infer that weight management in family practice with patients who are overweight or obese is challenged by the complexity of the task and the perceived motivation of patients. It needs to be facilitated by positive open communication and programs tailored to patient needs, preferences, and health literacy to be successful.ConclusionsProviding positive weight management in family practice requires ongoing commitment and an open and trusting therapeutic relationship between providers and patients. Behaviour change can be achieved through timely and considered interactions that target individual preferences, are tailored to health literacy, and are consistent and positive in their messaging. Ongoing support of family practices is required through funding and policy changes and additional avenues for referral and adjunctive interventions are required to provide comprehensive weight management within this setting.

Multi-dimensional safety risk assessment on coal mines under the profitability dilemma

China is a major coal producer, with huge differences in coal production and safety situations between the South and the North. Taking province A as an example, its coal enterprises have low output, poor efficiency, backward equipment, and low-quality personnel. The output accounts for 0.08% of the country, and the number of deaths accounts for 2.2% of the country, the safety situation of coal enterprises in province A is severe. In order to study the safety risk situation of coal mines under difficult conditions, this paper screens 98 factor indexes including multiple subjects such as enterprise managers, front-line workers, government supervisors, external environment, work quality, stress factors, economic factors, and other dimensions. For different data, the indicator weights were calculated using triangular fuzzy number, entropy weight method, CRITIC method, and three rough set methods in a total of six methods. The comprehensive weights of the indicators were obtained using the proposed new comprehensive weight method. The current situation of safety work of four coal mining enterprises and three levels of government supervision departments was evaluated, and the evaluation results were compared with other existing data to verify the reliability of the evaluation system. The horizontal comparison of the evaluation results indicates the main problems of each subject; the longitudinal comparison points out the problems that need to be solved with the assistance of higher-level enterprises and the central government, and corresponding suggestions for coal mining enterprises and government departments are put forward to reduce the safety risks of troubled coal mining enterprises.

Evaluation and design of dining room chair based on analytic hierarchy process (AHP) and fuzzy AHP

From the perspective of user needs, a design evaluation system for dining room chairs that can meet user needs was established. Based on the analytic hierarchy process (AHP), the user needs of a dining room chair were quantitatively analyzed by combining qualitative and quantitative methods. Moreover, the comprehensive weight ranking of 14 factors in the object hierarchy was obtained, which provided the design focus and quantitative indexes for designers in the early stage of dining room chair design. Then, in the later stage of dining room chair design, the fuzzy analytic hierarchy process (FAHP) method was used to quantitatively evaluate the three design schemes and obtain the optimal design scheme. The experimental results showed that the user needs evaluation results were positively correlated with the “excellent” grade in the FAHP method. This indicated that the evaluation system realized a symmetry, reliability, and effectiveness between the user needs evaluation and FAHP. Therefore, it can be concluded that this evaluation system based on AHP and FAHP proposed in this study has reliability and validity, and it can be used for design evaluation to judge the popularity of products, enhance the competitiveness of products, and reduce product design costs.

A novel method of key meta-action unit integrated identification for CNC machine tool reliability

There are many parts in CNC (computer numerical control) machine tool. Considering the time and economy, it is impossible to analyse them one by one. In order to reduce the blindness of researchers in choosing analysis objects, it is necessary to identify the key parts of CNC machine tool. MAU (meta-action unit) is the smallest structure that can reflect the function and performance of CNC machine tool, so it is taken as the research object. A new method for key MAU identification of CNC machine tool is proposed, as follows. Firstly, all the meta-action units were obtained by the FMA (function-motion-action) decomposition method, and the harmfulness was selected to analyze the influence of MAU on the reliability of CNC machine tool. Secondly, fuzzy theory is integrated into RPN (risk priority number) to obtain the harmfulness of MAU. Thirdly, the subjective weight of the harmfulness about the MAU was obtained by the combination of MAHP (modified analytic hierarchy process) and optimal sequence diagram method, and the objective weight was obtained by CRITIC (criteria importance though intercrieria correlation) method. Fourthly, the subjective and objective weights were integrated by a linear weighting method, and the result were taken as the comprehensive weight of the harmfulness of MAU. Finally, the harmfulness of the MAU could be obtained by its evaluation value and weight, and the MAU with greater impact on the reliability of CNC machine tool could be obtained by Pareto principle, which is the key MAU. A CNC machine tool made in China is analysised, and the effectiveness of the proposed method is verified by the comparison of various methods and experimental analysis.