Two simple, easy and correct process capability indices are presented in this paper which is based on the investigation of the actual management situation of manufacture process in the medium or small enterprise of ou...Two simple, easy and correct process capability indices are presented in this paper which is based on the investigation of the actual management situation of manufacture process in the medium or small enterprise of our country, and the applicability analysis for the evaluating methods of process capability. The coincidental degree of distribution center between the product quality and the spec tolerance is considered in the method, and the parameter of actual standard deviation is used. So the indices have higher accuracy and reflect the essential aspect of the problem.展开更多
This paper presents a method for robust tolerance design in terms of Process Capability Indices (PCI) . The component tolerance and the suitable manufacturing processes can be selected based on the real manufacturing ...This paper presents a method for robust tolerance design in terms of Process Capability Indices (PCI) . The component tolerance and the suitable manufacturing processes can be selected based on the real manufacturing context. The robustness of design feasibility under the effect of uncertainties is also discussed. A comparison between the results obtained by the proposed model and other methods indicates that robust and reliable tolerance can be obtained.展开更多
The existing research of process capability indices of multiple quality characteristics mainly focuses on nonconforming of process output, the concept development of tmivariate process capability indices, quality loss...The existing research of process capability indices of multiple quality characteristics mainly focuses on nonconforming of process output, the concept development of tmivariate process capability indices, quality loss function and various comprehensive evaluation methods. The multivariate complexity increases the computation difficulty of multivariate process capability indices（MPCI）, which makes them hard to be used in practice. In this paper, a new PCA-based MPCI approach is proposed to assess the production capability of the processes that involve multiple product quality characteristics. This approach first transforms the original quality variables into standardized normal variables. MPCI measures are then provided based on the Taam index. Moreover, the statistical properties of these MPCIs, such as confidence intervals and lower confidence bound, are given to let the practitioners understand the capability indices as random variables instead of deterministic variables. A real manufacturing data set and a synthetic data set are used to demonstrate the effectiveness of the proposed method. An implementation procedure is also provided for quality engineers to apply our MPCI approach in their manufacturing processes. The case studies demonstrate the effectiveness and feasibility of this new kind of MPCI, which is easier to be used in production practice. The proposed research provides a novel approach of MPCI calculation.展开更多
Achieving Six-Sigma process capability starts with l istening to the Voice of the Customers, and it becomes a reality by combining th e People Power and the Process Power of the organisation. This paper presents a Six...Achieving Six-Sigma process capability starts with l istening to the Voice of the Customers, and it becomes a reality by combining th e People Power and the Process Power of the organisation. This paper presents a Six-Sigma implementation case study carried out in a magnet manufacturing compa ny, which produces bearing magnets to be used in energy meters. If the thickness of the produced bearing magnets is between 2.35 mm and 2.50 mm, they will be ac cepted by the customers. All the time the company could not produce the bearing magnets within the specified thickness range, as their process distribution was flat with 2.20 mm as lower control limit and 2.60 mm as upper control limit. This resulted in a huge loss in the form of non-conformities, loss of time and goodwill. The process capability of the company then was around 0.40. Organisat ion restructuring was carried out to reap the benefit of the People Power of the organisation. Statistically designed experiments (Taguchi Method based Design o f Experiments), Online quality control tools (Statistical Process Control To ols) were effectively used to complete the DMAIC (Define, Measure, Analyse, Impr ove and Control) cycle to reap the benefit of the Process Power of the organisat ion. Presently the company enjoys a process capability of 1.75, a way towards Si x-Sigma Process Capability.展开更多
Process Capability Analysis (PCA) is a powerful too l to assess the ability of a process for manufacturing product that meets specific ations. The larger process capability index implies the higher process yield, a nd...Process Capability Analysis (PCA) is a powerful too l to assess the ability of a process for manufacturing product that meets specific ations. The larger process capability index implies the higher process yield, a nd the larger process capability index also indicates the lower process expected loss. Chen et al. (2001) has applied indices C pu, C pl, and C pk for evaluating the process capability for a multi-process product wi th smaller-the-better, larger-the-better, and nominal-the-best specificati ons respectively. However, C pk cannot reasonably reflect the process expected loss. In this paper, index C pn is selected to replace C pk. Indices C pu, C pl, and C pn are used to evalu ate the entire process capability for a multi-process product with smaller-the -better, larger-the-better, and nominal-the-best specifications respectivel y. An integrated process capability index for a multi-process product is propo sed. The relationship between process capability index and the process yield is introduced. A multi-process capability analysis chart (MPCAC), reasonably rev ealing the status of process capability for the entire product, is constructed f or practical application. An evaluating procedure of the process capability for the entire product is also provided.展开更多
Mechanical properties and low cycle fatigue are two factors that must be considered in developin gnew type steel for shock absorption. Process capability and process control are significant factors in achieving the pu...Mechanical properties and low cycle fatigue are two factors that must be considered in developin gnew type steel for shock absorption. Process capability and process control are significant factors in achieving the purpose of research and development programs. Often-used evaluation methods failed to measure processyield and process centering ; so this paper uses Taguchi loss function as basis to establish an evaluation methodand the steps for assessing the quality of mechanical properties and process control of an iron and steel manu-facturer. The establishment of this method can serve the research and development and manufacturing industry and lay a foundation in enhancing its process control ability to select better manufacturing processes that are more reliable than decision making by using the other commonly used methods.展开更多
Statistical Quality Control （SQC） is used to analyze and monitor quality characteristic measurements of normal neonatal weight in a maternity clinic in Banjarmasin in this paper. The objective of this study is to as...Statistical Quality Control （SQC） is used to analyze and monitor quality characteristic measurements of normal neonatal weight in a maternity clinic in Banjarmasin in this paper. The objective of this study is to assist medical practitioners in observing pregnant women to deliver their babies with normal weight. It is also assumed that pregnant women who delivered their babies in the clinic have been monitored during their nine-month pregnancy. Thus, they can manage their own pregnancy to deliver normal weight babies. The use of Statistical Process Control （SPC） tools, such as frequency histogram, probability plot, and the implementation of Shewhart, R, and S control charts as primary techniques, are presented to display the monitoring aspects of the process. In addition, Process Capability Analysis （PCA） is performed to ensure that the process outcomes are capable of meeting certain requirements or specifications. The Process Capability Ratio （PCR） for the process is also presented. This analysis is an essential part of an overall quality improvement program.展开更多
A process capability study is performed for the turning process on a general purpose center lathe in order to verify the process performance and machine ability to perform within specified tolerance limit. The process...A process capability study is performed for the turning process on a general purpose center lathe in order to verify the process performance and machine ability to perform within specified tolerance limit. The process and machine capability indices were measured to determine the process and machine adequacy for industrial application. The tolerance limits were obtained from the given nominal size of the shaft, using the basic hole system and 90 sample shafts were turned on the lathe machine to specification for varying spindle speed and feed rate of the lathe. Three (3) samples were randomly selected for the turning process of a combination of the spindle speed and feed rate as a subgroup size for a total subgroup of thirty (30). The diameters (representing the quality characteristics) were used to generate control charts and capability histogram for the process. The process is within statistical control but found incapable of meeting up to specification because the capability index (C<sub>p</sub>) measured was less than 1 and the machine capability for industrial application is not adequate.展开更多
Autocorrelation is prevalent in continuous production processes, such as the processes in the chemical and pharmaceutical industries. With the development of measurement technology and data acquisition technology, sam...Autocorrelation is prevalent in continuous production processes, such as the processes in the chemical and pharmaceutical industries. With the development of measurement technology and data acquisition technology, sampling frequency is getting higher and the existence of autocorrelation cannot be ignored. This paper analyzes five estimation schemes of process capability for autocorrelated data. Comparisons among these schemes are discussed for small sample and large sample. In conclusion, this paper gives a procedure of process capability analysis for autocorrelated data.展开更多
This paper presents a systematic multivariate process capability index （MPCI） method, which may provide references for assuring and improving process quality levels while achieving an overall evaluation of process q...This paper presents a systematic multivariate process capability index （MPCI） method, which may provide references for assuring and improving process quality levels while achieving an overall evaluation of process quality. The system method includes a spatial MPCI model for multivariate normal distribution data, MPCI model based on factor weight for multivariate no-normal distribution application, and MPCI model based on yield foryield application. At last, examples for calculating MPCI are given, and the experimental results show that this systematic method is effective and practical.展开更多
After analyzing the multivariate Cpm method （Chan et al. 1991）, this paper presents a spatial multivariate process capability index （PCI） method, which can solve a multivariate off-centered case and may provide re...After analyzing the multivariate Cpm method （Chan et al. 1991）, this paper presents a spatial multivariate process capability index （PCI） method, which can solve a multivariate off-centered case and may provide references for assuring and improving process quality level while achieving an overall evaluation of process quality. Examples for calculating multivariate PCI are given and the experimental results show that the systematic method presented is effective and actual.展开更多
In recent years, there has been mounting interest i n measuring process performance in manufacturing industry. Based on analyzing the process capability indices, a production department can trace and improve a poor pr...In recent years, there has been mounting interest i n measuring process performance in manufacturing industry. Based on analyzing the process capability indices, a production department can trace and improve a poor process to enhance quality levels and satisfy customers. The process capabilit y analysis can also serve as an important reference for making decisions for imp roving the global quality of all products. Since C p and C pk are failed to account for process centering, the index C pm is developed. The index C pm takes the process centering into consideration and is su itable for the processes with nominal-the-best type. There are other indices l ike C pu and C pl, and those indices are used for unilateral s pecification processes. Chou (1994) developed a procedure using estimators of C p, C pu and C pl for practitioners to determine whether two p rocesses are equal capability or not. For bilateral specifications processes, i ndex C p is failed to measure process yield and process centering. Thus, th e index C pm is used to develop a similar procedure for practitioners t o determine whether two processes are equal capability or not. The decisions mad e using the procedure to select the better supplier are, of course, more reliabl e.展开更多
The processing capability is vital for the wide applications of materials to forge structures as-demand.Graphene-based macroscopic materials have shown excellent mechanical and functional properties.However,different ...The processing capability is vital for the wide applications of materials to forge structures as-demand.Graphene-based macroscopic materials have shown excellent mechanical and functional properties.However,different from usual polymers and metals,graphene solids exhibit limited deformability and processibility for precise forming.Here,we present a precise thermoplastic forming of graphene materials by polymer intercalation from graphene oxide(GO)precursor.The intercalated polymer enables the thermoplasticity of GO solids by thermally activated motion of polymer chains.We detect a critical minimum containing of intercalated polymer that can expand the interlayer spacing exceeding 1.4 nm to activate thermoplasticity,which becomes the criteria for thermal plastic forming of GO solids.By thermoplastic forming,the flat GO-composite films are forged to Gaussian curved shapes and imprinted to have surface relief patterns with size precision down to 360 nm.The plastic-formed structures maintain the structural integration with outstanding electrical(3.07×10^(5) S m^(−1))and thermal conductivity(745.65 W m^(−1) K^(−1))after removal of polymers.The thermoplastic strategy greatly extends the forming capability of GO materials and other layered materials and promises versatile structural designs for more broad applications.展开更多
Nowadays, with the rapid progress and development of the Chinese society, people’s material level has been continuously improved, and the demand for electricity has also been increasing year by year. For thermal powe...Nowadays, with the rapid progress and development of the Chinese society, people’s material level has been continuously improved, and the demand for electricity has also been increasing year by year. For thermal power plants, it is of great importance to strictly control the feedwater quality and to conduct real-time tracking and supervision, as well as to ensure the safety of the production process. In this paper, we take the boiler feedwater quality in the production process as the research object. First of all, the cause-and-effect diagram is used to find out the reasons for the deviation of feedwater quality;Secondly, each index of feedwater is analyzed by multiple linear regression method to find out the key variables affecting the change of its pH value, so as to develop and implement improvement measures;Finally, the pH value is compared and verified by control chart and process capability analysis, and relevant improvement suggestions and countermeasures are proposed.展开更多
With the expansion of the application range and network scale of wireless sensor networks in recent years,WSNs often generate data surges and delay queues during the transmission process,causing network paralysis,even...With the expansion of the application range and network scale of wireless sensor networks in recent years,WSNs often generate data surges and delay queues during the transmission process,causing network paralysis,even resulting in local or global congestion.In this paper,a dynamically Adjusted Duty Cycle for Optimized Congestion based on a real-time Queue Length(ADCOC)scheme is proposed.In order to improve the resource utilization rate of network nodes,we carried out optimization analysis based on the theory and applied it to the adjustment of the node’s duty cycle strategy.Using this strategy to ensure that the network lifetime remains the same,can minimize system delay and maximize energy efficiency.Firstly,the problems of the existing RED algorithm are analyzed.We introduce the improved SIG-RED algorithm into the ADCOC mechanism.As the data traffic changes,the RED protocol cannot automatically adjust the duty cycle.A scheduler is added to the buffer area manager,referring to a weighted index of network congestion,which can quickly determine the status of network congestion.The value of the weighting coefficient W is adjusted by the Bayesian method.The scheduler preferably transmits severely urgent data,alleviating the memory load.Then we combined improved data fusion technology and information gain methods to adjust the duty cycle dynamically.By simulating the algorithm,it shows that it has faster convergence speed and smaller queue jitter.Finally,we combine the adjusted congestion weight and the duty cycle growth value to adjust the data processing rate capability in the real-time network by dynamically adjusting it to adapt to bursts of data streams.Thus,the frequency of congestion is reduced to ensure that the system has higher processing efficiency and good adaptability.展开更多
The industrial organisations have a vested interest in quality and its practices in making a quantum leap, thereby requiring proper refocusing and rethinking. This is targeted seriously towards firms acquiring Knowled...The industrial organisations have a vested interest in quality and its practices in making a quantum leap, thereby requiring proper refocusing and rethinking. This is targeted seriously towards firms acquiring Knowledge Systems （KS） in order to nurture the employees＇ capabilities. Therefore, to enhance performances and their highly creative direction takes consideration of QE （quality engineering） and KS and disciplines complementary to each other. Additionally, the flow of operations and activities of the KS through the application of quality engineering （QE） principles is according to the view of Japanese engineer Taguchi. This aims to achieve good quality in the product design and processes, and also to anticipate problems that may occur before the shipping of the products. In this study, the use of quality control engineering and Taguchi＇s function methods in determining these properties and the loss caused by the company will be examined. However, the adopted approach of study scope to the society will aid KS. Also, efforts in this direction motivate the employment of a statistical method by Taguchi which relied on the principle of target-oriented quality, representing the value characterising the product quality.展开更多
The alternating electromagnetic(EM) field is one of the most sensitive physical fields related to earthquakes. There have been a number of publications reporting EM anomalies associated with earthquakes. With increasi...The alternating electromagnetic(EM) field is one of the most sensitive physical fields related to earthquakes. There have been a number of publications reporting EM anomalies associated with earthquakes. With increasing applications and research of artificial-source extremely low frequency EM and satellite EM technologies in earthquake studies, the amount of observed data from the alternating EM method increases rapidly and exponentially, so it is imperative to develop suitable and effective methods for processing and analyzing the influx of big data. This paper presents research on the self-adaptive filter and wavelet techniques and their applications to analyzing EM data obtained from ground measurements and satellite observations, respectively. Analysis results show that the self-adaptive filter method can identify both natural- and artificial-source EM signals, and enhance the ratio between signal and noise of EM field spectra, apparent resistivity, and others. The wavelet analysis is capable of detecting possible correlation between EM anomalies and seismic events. These techniques are effective in processing and analyzing massive data obtained from EM observations.展开更多
Smart manufacturing still remains critical challenges for pharmaceutical manufacturing.Here,an original data-driven engineering framework was proposed to tackle the challenges.Firstly,from sporadic indicators to five ...Smart manufacturing still remains critical challenges for pharmaceutical manufacturing.Here,an original data-driven engineering framework was proposed to tackle the challenges.Firstly,from sporadic indicators to five kinds of systematic quality characteristics,nearly 2,000,000 real-world data points were successively characterized from Ginkgo Folium tablet manufacturing.Then,from simplex to the multivariate system,the digital process capability diagnosis strategy was proposed by multivariate C_(pk)integrated Bootstrap-t.The C_(pk)of Ginkgo Folium extracts,granules,and tablets were discovered,which was 0.59,0.42,and 0.78,respectively,indicating a relatively weak process capability,especially in granulating.Furthermore,the quality traceability was discovered from unit to end-to-end analysis,which decreased from 2.17 to 1.73.This further proved that attention should be paid to granulating to improve the quality characteristic.In conclusion,this paper provided a data-driven engineering strategy empowering industrial innovation to face the challenge of smart pharmaceutical manufacturing.展开更多
This study provides a framework of target costing to extend its original scope when the underlying distribution is non-normal. The new specification limits can be derived by listening to the market price from Taguchi ...This study provides a framework of target costing to extend its original scope when the underlying distribution is non-normal. The new specification limits can be derived by listening to the market price from Taguchi loss function. Later, the new specification limits can be linked through the non-normality-based C^^pk value along with non-normality-based X^^-Rcontrol charts to derive goal control limits. Moreover, an example is provided to illustrate the usefulness of the proposed framework of target costing by relentlessly reducing cost and improving product quality to gain competitiveness in the marketplace.展开更多
This paper studies an electronic counter-counter measures（ECCM） scheme combating against deceptive electronic counter measure（ECM） techniques. An adaptive detector exploiting generalized likelihood ratio test（GRL...This paper studies an electronic counter-counter measures（ECCM） scheme combating against deceptive electronic counter measure（ECM） techniques. An adaptive detector exploiting generalized likelihood ratio test（GRLT） criterion is applied to detect the presence of deceptive jamming in fractional Fourier transform（Fr FT） domain. First, the generating mechanism of spurious frequencies is analyzed based on the Volterra serial. The proposed nonlinear distortion model based on power amplifier behavior is robust in distortion analysis when the memory effect is considered.Second, a modified adaptive beamformer orthogonal rejection test（ABORT） like detector in closed form is built. The proposed detector can discriminate the echo and deceptive jamming adaptively by exploiting primary data and secondary data. This ECCM scheme is capable of guaranteeing the performance without the restriction of orthogonality, which is essential for the ABORT detectors. The expansion to radar network is discussed as a special case at the final part of this paper. Numerical simulations demonstrate the effectiveness of the proposed method.展开更多
基金the Development Foundation of Science and Technology of Shanghai Municipal Commission of Education(97AJ05)
文摘Two simple, easy and correct process capability indices are presented in this paper which is based on the investigation of the actual management situation of manufacture process in the medium or small enterprise of our country, and the applicability analysis for the evaluating methods of process capability. The coincidental degree of distribution center between the product quality and the spec tolerance is considered in the method, and the parameter of actual standard deviation is used. So the indices have higher accuracy and reflect the essential aspect of the problem.
文摘This paper presents a method for robust tolerance design in terms of Process Capability Indices (PCI) . The component tolerance and the suitable manufacturing processes can be selected based on the real manufacturing context. The robustness of design feasibility under the effect of uncertainties is also discussed. A comparison between the results obtained by the proposed model and other methods indicates that robust and reliable tolerance can be obtained.
基金supported by National Natural Science Foundation of China(Grant Nos.70802043,71225006 and 71002105)
文摘The existing research of process capability indices of multiple quality characteristics mainly focuses on nonconforming of process output, the concept development of tmivariate process capability indices, quality loss function and various comprehensive evaluation methods. The multivariate complexity increases the computation difficulty of multivariate process capability indices（MPCI）, which makes them hard to be used in practice. In this paper, a new PCA-based MPCI approach is proposed to assess the production capability of the processes that involve multiple product quality characteristics. This approach first transforms the original quality variables into standardized normal variables. MPCI measures are then provided based on the Taam index. Moreover, the statistical properties of these MPCIs, such as confidence intervals and lower confidence bound, are given to let the practitioners understand the capability indices as random variables instead of deterministic variables. A real manufacturing data set and a synthetic data set are used to demonstrate the effectiveness of the proposed method. An implementation procedure is also provided for quality engineers to apply our MPCI approach in their manufacturing processes. The case studies demonstrate the effectiveness and feasibility of this new kind of MPCI, which is easier to be used in production practice. The proposed research provides a novel approach of MPCI calculation.
文摘Achieving Six-Sigma process capability starts with l istening to the Voice of the Customers, and it becomes a reality by combining th e People Power and the Process Power of the organisation. This paper presents a Six-Sigma implementation case study carried out in a magnet manufacturing compa ny, which produces bearing magnets to be used in energy meters. If the thickness of the produced bearing magnets is between 2.35 mm and 2.50 mm, they will be ac cepted by the customers. All the time the company could not produce the bearing magnets within the specified thickness range, as their process distribution was flat with 2.20 mm as lower control limit and 2.60 mm as upper control limit. This resulted in a huge loss in the form of non-conformities, loss of time and goodwill. The process capability of the company then was around 0.40. Organisat ion restructuring was carried out to reap the benefit of the People Power of the organisation. Statistically designed experiments (Taguchi Method based Design o f Experiments), Online quality control tools (Statistical Process Control To ols) were effectively used to complete the DMAIC (Define, Measure, Analyse, Impr ove and Control) cycle to reap the benefit of the Process Power of the organisat ion. Presently the company enjoys a process capability of 1.75, a way towards Si x-Sigma Process Capability.
文摘Process Capability Analysis (PCA) is a powerful too l to assess the ability of a process for manufacturing product that meets specific ations. The larger process capability index implies the higher process yield, a nd the larger process capability index also indicates the lower process expected loss. Chen et al. (2001) has applied indices C pu, C pl, and C pk for evaluating the process capability for a multi-process product wi th smaller-the-better, larger-the-better, and nominal-the-best specificati ons respectively. However, C pk cannot reasonably reflect the process expected loss. In this paper, index C pn is selected to replace C pk. Indices C pu, C pl, and C pn are used to evalu ate the entire process capability for a multi-process product with smaller-the -better, larger-the-better, and nominal-the-best specifications respectivel y. An integrated process capability index for a multi-process product is propo sed. The relationship between process capability index and the process yield is introduced. A multi-process capability analysis chart (MPCAC), reasonably rev ealing the status of process capability for the entire product, is constructed f or practical application. An evaluating procedure of the process capability for the entire product is also provided.
文摘Mechanical properties and low cycle fatigue are two factors that must be considered in developin gnew type steel for shock absorption. Process capability and process control are significant factors in achieving the purpose of research and development programs. Often-used evaluation methods failed to measure processyield and process centering ; so this paper uses Taguchi loss function as basis to establish an evaluation methodand the steps for assessing the quality of mechanical properties and process control of an iron and steel manu-facturer. The establishment of this method can serve the research and development and manufacturing industry and lay a foundation in enhancing its process control ability to select better manufacturing processes that are more reliable than decision making by using the other commonly used methods.
文摘Statistical Quality Control （SQC） is used to analyze and monitor quality characteristic measurements of normal neonatal weight in a maternity clinic in Banjarmasin in this paper. The objective of this study is to assist medical practitioners in observing pregnant women to deliver their babies with normal weight. It is also assumed that pregnant women who delivered their babies in the clinic have been monitored during their nine-month pregnancy. Thus, they can manage their own pregnancy to deliver normal weight babies. The use of Statistical Process Control （SPC） tools, such as frequency histogram, probability plot, and the implementation of Shewhart, R, and S control charts as primary techniques, are presented to display the monitoring aspects of the process. In addition, Process Capability Analysis （PCA） is performed to ensure that the process outcomes are capable of meeting certain requirements or specifications. The Process Capability Ratio （PCR） for the process is also presented. This analysis is an essential part of an overall quality improvement program.
文摘A process capability study is performed for the turning process on a general purpose center lathe in order to verify the process performance and machine ability to perform within specified tolerance limit. The process and machine capability indices were measured to determine the process and machine adequacy for industrial application. The tolerance limits were obtained from the given nominal size of the shaft, using the basic hole system and 90 sample shafts were turned on the lathe machine to specification for varying spindle speed and feed rate of the lathe. Three (3) samples were randomly selected for the turning process of a combination of the spindle speed and feed rate as a subgroup size for a total subgroup of thirty (30). The diameters (representing the quality characteristics) were used to generate control charts and capability histogram for the process. The process is within statistical control but found incapable of meeting up to specification because the capability index (C<sub>p</sub>) measured was less than 1 and the machine capability for industrial application is not adequate.
基金supported by National Natural Science Foundation of China(70772019,70621061)National Social Science Foundation of China(08BTJ002)
文摘Autocorrelation is prevalent in continuous production processes, such as the processes in the chemical and pharmaceutical industries. With the development of measurement technology and data acquisition technology, sampling frequency is getting higher and the existence of autocorrelation cannot be ignored. This paper analyzes five estimation schemes of process capability for autocorrelated data. Comparisons among these schemes are discussed for small sample and large sample. In conclusion, this paper gives a procedure of process capability analysis for autocorrelated data.
文摘This paper presents a systematic multivariate process capability index （MPCI） method, which may provide references for assuring and improving process quality levels while achieving an overall evaluation of process quality. The system method includes a spatial MPCI model for multivariate normal distribution data, MPCI model based on factor weight for multivariate no-normal distribution application, and MPCI model based on yield foryield application. At last, examples for calculating MPCI are given, and the experimental results show that this systematic method is effective and practical.
基金Project supported by the Natural Science Foundation of Shaanxi Province(No.2012JQ8048)the Basic Research Foundation of North-western Polytechnical University(No.JC20110232)
文摘After analyzing the multivariate Cpm method （Chan et al. 1991）, this paper presents a spatial multivariate process capability index （PCI） method, which can solve a multivariate off-centered case and may provide references for assuring and improving process quality level while achieving an overall evaluation of process quality. Examples for calculating multivariate PCI are given and the experimental results show that the systematic method presented is effective and actual.
文摘In recent years, there has been mounting interest i n measuring process performance in manufacturing industry. Based on analyzing the process capability indices, a production department can trace and improve a poor process to enhance quality levels and satisfy customers. The process capabilit y analysis can also serve as an important reference for making decisions for imp roving the global quality of all products. Since C p and C pk are failed to account for process centering, the index C pm is developed. The index C pm takes the process centering into consideration and is su itable for the processes with nominal-the-best type. There are other indices l ike C pu and C pl, and those indices are used for unilateral s pecification processes. Chou (1994) developed a procedure using estimators of C p, C pu and C pl for practitioners to determine whether two p rocesses are equal capability or not. For bilateral specifications processes, i ndex C p is failed to measure process yield and process centering. Thus, th e index C pm is used to develop a similar procedure for practitioners t o determine whether two processes are equal capability or not. The decisions mad e using the procedure to select the better supplier are, of course, more reliabl e.
基金the support of the National Natural Science Foundation of China(Nos.51803177,51973191,51533008,and 51636002)National Key R&D Program of China(No.2016YFA0200200)+5 种基金the China Postdoctoral Science Foundation(No.2021M690134)Hundred Talents Program of Zhejiang University(188020*194231701/113)Key Research and Development Plan of Zhejiang Province(2018C01049)the National Postdoctoral Program for Innovative Talents(No.BX201700209)the Fundamental Research Funds for the Central Universities(2021FZZX001-17),the Natural Science Foundation of Jiangsu Province(BK20210353)the Fundamental Research Funds for the Central Universities(No.30920041106).
文摘The processing capability is vital for the wide applications of materials to forge structures as-demand.Graphene-based macroscopic materials have shown excellent mechanical and functional properties.However,different from usual polymers and metals,graphene solids exhibit limited deformability and processibility for precise forming.Here,we present a precise thermoplastic forming of graphene materials by polymer intercalation from graphene oxide(GO)precursor.The intercalated polymer enables the thermoplasticity of GO solids by thermally activated motion of polymer chains.We detect a critical minimum containing of intercalated polymer that can expand the interlayer spacing exceeding 1.4 nm to activate thermoplasticity,which becomes the criteria for thermal plastic forming of GO solids.By thermoplastic forming,the flat GO-composite films are forged to Gaussian curved shapes and imprinted to have surface relief patterns with size precision down to 360 nm.The plastic-formed structures maintain the structural integration with outstanding electrical(3.07×10^(5) S m^(−1))and thermal conductivity(745.65 W m^(−1) K^(−1))after removal of polymers.The thermoplastic strategy greatly extends the forming capability of GO materials and other layered materials and promises versatile structural designs for more broad applications.
文摘Nowadays, with the rapid progress and development of the Chinese society, people’s material level has been continuously improved, and the demand for electricity has also been increasing year by year. For thermal power plants, it is of great importance to strictly control the feedwater quality and to conduct real-time tracking and supervision, as well as to ensure the safety of the production process. In this paper, we take the boiler feedwater quality in the production process as the research object. First of all, the cause-and-effect diagram is used to find out the reasons for the deviation of feedwater quality;Secondly, each index of feedwater is analyzed by multiple linear regression method to find out the key variables affecting the change of its pH value, so as to develop and implement improvement measures;Finally, the pH value is compared and verified by control chart and process capability analysis, and relevant improvement suggestions and countermeasures are proposed.
基金This work is supported by“National Science Foundation of Hunan Province,China”under Grant 2020JJ4757.
文摘With the expansion of the application range and network scale of wireless sensor networks in recent years,WSNs often generate data surges and delay queues during the transmission process,causing network paralysis,even resulting in local or global congestion.In this paper,a dynamically Adjusted Duty Cycle for Optimized Congestion based on a real-time Queue Length(ADCOC)scheme is proposed.In order to improve the resource utilization rate of network nodes,we carried out optimization analysis based on the theory and applied it to the adjustment of the node’s duty cycle strategy.Using this strategy to ensure that the network lifetime remains the same,can minimize system delay and maximize energy efficiency.Firstly,the problems of the existing RED algorithm are analyzed.We introduce the improved SIG-RED algorithm into the ADCOC mechanism.As the data traffic changes,the RED protocol cannot automatically adjust the duty cycle.A scheduler is added to the buffer area manager,referring to a weighted index of network congestion,which can quickly determine the status of network congestion.The value of the weighting coefficient W is adjusted by the Bayesian method.The scheduler preferably transmits severely urgent data,alleviating the memory load.Then we combined improved data fusion technology and information gain methods to adjust the duty cycle dynamically.By simulating the algorithm,it shows that it has faster convergence speed and smaller queue jitter.Finally,we combine the adjusted congestion weight and the duty cycle growth value to adjust the data processing rate capability in the real-time network by dynamically adjusting it to adapt to bursts of data streams.Thus,the frequency of congestion is reduced to ensure that the system has higher processing efficiency and good adaptability.
文摘The industrial organisations have a vested interest in quality and its practices in making a quantum leap, thereby requiring proper refocusing and rethinking. This is targeted seriously towards firms acquiring Knowledge Systems （KS） in order to nurture the employees＇ capabilities. Therefore, to enhance performances and their highly creative direction takes consideration of QE （quality engineering） and KS and disciplines complementary to each other. Additionally, the flow of operations and activities of the KS through the application of quality engineering （QE） principles is according to the view of Japanese engineer Taguchi. This aims to achieve good quality in the product design and processes, and also to anticipate problems that may occur before the shipping of the products. In this study, the use of quality control engineering and Taguchi＇s function methods in determining these properties and the loss caused by the company will be examined. However, the adopted approach of study scope to the society will aid KS. Also, efforts in this direction motivate the employment of a statistical method by Taguchi which relied on the principle of target-oriented quality, representing the value characterising the product quality.
基金supported by the National Natural Science Foundation of China(Grant Nos.41374077,41074047)CEA-NASCC Dragon Project Ⅲ(Grant No.10671)Special Public Benefit Program for Earthquake Study(Grant No.200808010)
文摘The alternating electromagnetic(EM) field is one of the most sensitive physical fields related to earthquakes. There have been a number of publications reporting EM anomalies associated with earthquakes. With increasing applications and research of artificial-source extremely low frequency EM and satellite EM technologies in earthquake studies, the amount of observed data from the alternating EM method increases rapidly and exponentially, so it is imperative to develop suitable and effective methods for processing and analyzing the influx of big data. This paper presents research on the self-adaptive filter and wavelet techniques and their applications to analyzing EM data obtained from ground measurements and satellite observations, respectively. Analysis results show that the self-adaptive filter method can identify both natural- and artificial-source EM signals, and enhance the ratio between signal and noise of EM field spectra, apparent resistivity, and others. The wavelet analysis is capable of detecting possible correlation between EM anomalies and seismic events. These techniques are effective in processing and analyzing massive data obtained from EM observations.
基金co-National Outstanding Youth Science Fund Project of National Natural Science Foundation of China(Grant No.82022073,China)Major scientific and technological R&D projects in Jiangxi Province(Grant No.20203ABC28W018,China)National Key Research and Development Program of China(Grant No.2018YFC1706900,China)。
文摘Smart manufacturing still remains critical challenges for pharmaceutical manufacturing.Here,an original data-driven engineering framework was proposed to tackle the challenges.Firstly,from sporadic indicators to five kinds of systematic quality characteristics,nearly 2,000,000 real-world data points were successively characterized from Ginkgo Folium tablet manufacturing.Then,from simplex to the multivariate system,the digital process capability diagnosis strategy was proposed by multivariate C_(pk)integrated Bootstrap-t.The C_(pk)of Ginkgo Folium extracts,granules,and tablets were discovered,which was 0.59,0.42,and 0.78,respectively,indicating a relatively weak process capability,especially in granulating.Furthermore,the quality traceability was discovered from unit to end-to-end analysis,which decreased from 2.17 to 1.73.This further proved that attention should be paid to granulating to improve the quality characteristic.In conclusion,this paper provided a data-driven engineering strategy empowering industrial innovation to face the challenge of smart pharmaceutical manufacturing.
文摘This study provides a framework of target costing to extend its original scope when the underlying distribution is non-normal. The new specification limits can be derived by listening to the market price from Taguchi loss function. Later, the new specification limits can be linked through the non-normality-based C^^pk value along with non-normality-based X^^-Rcontrol charts to derive goal control limits. Moreover, an example is provided to illustrate the usefulness of the proposed framework of target costing by relentlessly reducing cost and improving product quality to gain competitiveness in the marketplace.
文摘This paper studies an electronic counter-counter measures（ECCM） scheme combating against deceptive electronic counter measure（ECM） techniques. An adaptive detector exploiting generalized likelihood ratio test（GRLT） criterion is applied to detect the presence of deceptive jamming in fractional Fourier transform（Fr FT） domain. First, the generating mechanism of spurious frequencies is analyzed based on the Volterra serial. The proposed nonlinear distortion model based on power amplifier behavior is robust in distortion analysis when the memory effect is considered.Second, a modified adaptive beamformer orthogonal rejection test（ABORT） like detector in closed form is built. The proposed detector can discriminate the echo and deceptive jamming adaptively by exploiting primary data and secondary data. This ECCM scheme is capable of guaranteeing the performance without the restriction of orthogonality, which is essential for the ABORT detectors. The expansion to radar network is discussed as a special case at the final part of this paper. Numerical simulations demonstrate the effectiveness of the proposed method.
