The selection of context is not random but limited by linguistic communicators'cognitive environment.Sperber &Wilson propose a more persuasive inferential model on the basis of Grice's theory.They think la...The selection of context is not random but limited by linguistic communicators'cognitive environment.Sperber &Wilson propose a more persuasive inferential model on the basis of Grice's theory.They think language communication is a de ductive and inferential process in which the communicators deal with the information in the context,a set of assumptions,and finally infer the meaning.Since a discourse is the work of language and the product of the process of linguistic communication,the inferential model will also adapt to the discourse analysis.With the inferential model as its basic analyzing framework,this paper puts discourse in a dynamic communicative process to investigate how the discourse receiver selects the context to make the com munication succeed.展开更多
Temperature inferential control (TIC) is studied for a reactive distillation column with double reactive sections (RDC-DRSs) processing a hypothetical two-stage consecutive reversible reaction (A + B■C + D, C + B■E ...Temperature inferential control (TIC) is studied for a reactive distillation column with double reactive sections (RDC-DRSs) processing a hypothetical two-stage consecutive reversible reaction (A + B■C + D, C + B■E + D with αD > αB > αC > αA > αE). Because of the complicated dynamic behaviors, the controlled stages by sensitivity analysis lead to great steady-state deviations (SSDs) in top and bottom product purities. Since TIC involves considerably reduced settling times in comparison with direct composition control, small SSDs in product qualities correspond generally to small transient deviations (TDs) in product qualities. An objective function that measures SSDs in product qualities is formulated to represent the performance of a TIC system and an iterative procedure is devised to search for the best control configuration. The application of the procedure to the RDC-DRS gives considerably suppressed TDs and SSDs in top and bottom product qualities as compared with the one by sensitivity analysis. The method is simpler in principle and less computationally intensive than the current practice. These striking outcomes show the effectiveness of the proposed principle for the development of TIC systems for complicated reactive distillation columns.展开更多
The dividing wall column (DWC) is considered as a major breakthrough in distillation technology and has good prospect of industrialization. Model predictive control (MPC) is an advanced control strategy that has a...The dividing wall column (DWC) is considered as a major breakthrough in distillation technology and has good prospect of industrialization. Model predictive control (MPC) is an advanced control strategy that has acquired extensive applications in various industries. In this study, MPC is applied to the process for separating ethanol, n-propanol, and n-butanol ternary mixture in a fully thermally coupled DWC. Both composition control and tem- perature inferent/al control are considered. The multiobjective genetic algor/thm function "gamult/obj" in Matlab is used for the weight tuning of MPC. Comparisons are made between the control performances of MPC and PI strategies. Simulation results show that although both MPC and PI schemes can stabilize the DWC in case of feed disturbances, MPC generally behaves better than the PI strategy for both composition control and tempera- ture inferential control, resulting in a more stable and superior performance with lower values of integral of squared error (ISE).展开更多
Inferential models are widely used in the chemical industry to infer key process variables, which are challenging or expensive to measure, from other more easily measured variables. The aim of this paper is three-fold...Inferential models are widely used in the chemical industry to infer key process variables, which are challenging or expensive to measure, from other more easily measured variables. The aim of this paper is three-fold: to present a theoretical review of some of the well known linear inferential modeling techniques, to enhance the predictive ability of the regularized canonical correlation analysis (RCCA) method, and finally to compare the performances of these techniques and highlight some of the practical issues that can affect their predictive abilities. The inferential modeling techniques considered in this study include full rank modeling techniques, such as ordinary least square (OLS) regression and ridge regression (RR), and latent variable regression (LVR) techniques, such as principal component regression (PCR), partial least squares (PLS) regression, and regularized canonical correlation analysis (RCCA). The theoretical analysis shows that the loading vectors used in LVR modeling can be computed by solving eigenvalue problems. Also, for the RCCA method, we show that by optimizing the regularization parameter, an improvement in prediction accuracy can be achieved over other modeling techniques. To illustrate the performances of all inferential modeling techniques, a comparative analysis was performed through two simulated examples, one using synthetic data and the other using simulated distillation column data. All techniques are optimized and compared by computing the cross validation mean square error using unseen testing data. The results of this comparative analysis show that scaling the data helps improve the performances of all modeling techniques, and that the LVR techniques outperform the full rank ones. One reason for this advantage is that the LVR techniques improve the conditioning of the model by discarding the latent variables (or principal components) with small eigenvalues, which also reduce the effect of the noise on the model prediction. The results also show that PCR and PLS have comparable performances, and that RCCA can provide an advantage by optimizing its regularization parameter.展开更多
The inherent randomness,intermittence and volatility of wind power generation compromise the quality of the wind power system,resulting in uncertainty in the system’s optimal scheduling.As a result,it’s critical to ...The inherent randomness,intermittence and volatility of wind power generation compromise the quality of the wind power system,resulting in uncertainty in the system’s optimal scheduling.As a result,it’s critical to improve power quality and assure real-time power grid scheduling and grid-connected wind farm operation.Inferred statistics are utilized in this research to infer general features based on the selected information,confirming that there are differences between two forecasting categories:Forecast Category 1(0-11 h ahead)and Forecast Category 2(12-23 h ahead).In z-tests,the null hypothesis provides the corresponding quantitative findings.To verify the final performance of the prediction findings,five benchmark methodologies are used:Persistence model,LMNN(Multilayer Perceptron with LMlearningmethods),NARX(Nonlinear autoregressive exogenous neural networkmodel),LMRNN(RNNs with LM training methods)and LSTM(Long short-term memory neural network).Experiments using a real dataset show that the LSTM network has the highest forecasting accuracy when compared to other benchmark approaches including persistence model,LMNN,NARX network,and LMRNN,and the 23-steps forecasting accuracy has improved by 19.61%.展开更多
Multivariate statistical process monitoring and control (MSPM&C) methods for chemical process monitoring with statistical projection techniques such as principal component analysis (PCA) and partial least squares ...Multivariate statistical process monitoring and control (MSPM&C) methods for chemical process monitoring with statistical projection techniques such as principal component analysis (PCA) and partial least squares (PLS) are surveyed in this paper. The four-step procedure of performing MSPM&C for chemical process, modeling of processes, detecting abnormal events or faults, identifying the variable(s) responsible for the faults and diagnosing the source cause for the abnormal behavior, is analyzed. Several main research directions of MSPM&C reported in the literature are discussed, such as multi-way principal component analysis (MPCA) for batch process, statistical monitoring and control for nonlinear process, dynamic PCA and dynamic PLS, and on-line quality control by inferential models. Industrial applications of MSPM&C to several typical chemical processes, such as chemical reactor, distillation column, polymerization process, petroleum refinery units, are summarized. Finally, some concluding remarks and future considerations are made.展开更多
A latent variable regression algorithm with a regularization term(r LVR) is proposed in this paper to extract latent relations between process data X and quality data Y. In rLVR,the prediction error between X and Y is...A latent variable regression algorithm with a regularization term(r LVR) is proposed in this paper to extract latent relations between process data X and quality data Y. In rLVR,the prediction error between X and Y is minimized, which is proved to be equivalent to maximizing the projection of quality variables in the latent space. The geometric properties and model relations of rLVR are analyzed, and the geometric and theoretical relations among r LVR, partial least squares, and canonical correlation analysis are also presented. The rLVR-based monitoring framework is developed to monitor process-relevant and quality-relevant variations simultaneously. The prediction and monitoring effectiveness of rLVR algorithm is demonstrated through both numerical simulations and the Tennessee Eastman(TE) process.展开更多
A new on-line predictive monitoring and prediction model for periodic biological processes is proposed using the multiway non-Gaussian modeling. The basic idea of this approach is to use multiway non-Gaussian modeling...A new on-line predictive monitoring and prediction model for periodic biological processes is proposed using the multiway non-Gaussian modeling. The basic idea of this approach is to use multiway non-Gaussian modeling to extract some dominant key components from daily normal operation data in a periodic process, and subsequently combining these components with predictive statistical process monitoring techniques. The proposed predictive monitoring method has been applied to fault detection and diagnosis in the biological wastewater-treatment process, which is based on strong diurnal characteristics. The results show the power and advantages of the proposed predictive monitoring of a continuous process using the multiway predictive monitoring concept, which is thus able to give very useful conceptual results for a daily monitoring process and also enables a more rapid detection of the process fault than other traditional monitoring methods.展开更多
A maximum test in lieu of forcing a choice between the two dependent samples t-test and Wilcoxon signed-ranks test is proposed. The maximum test, which requires a new table of critical values, maintains nominal α whi...A maximum test in lieu of forcing a choice between the two dependent samples t-test and Wilcoxon signed-ranks test is proposed. The maximum test, which requires a new table of critical values, maintains nominal α while guaranteeing the maximum power of the two constituent tests. Critical values, obtained via Monte Carlo methods, are uniformly smaller than the Bonferroni-Dunn adjustment, giving it power superiority when testing for treatment alternatives of shift in location parameter when data are sampled from non-normal distributions.展开更多
Temperature difference control(TDC)schemes can clearly suppress the adverse influence of pressure variations on product quality control of various distillation columns(DCs)by employing temperature differences(TDs)betw...Temperature difference control(TDC)schemes can clearly suppress the adverse influence of pressure variations on product quality control of various distillation columns(DCs)by employing temperature differences(TDs)between the sensitive stage temperature(T_(S))and reference stage temperature(T_(R)),i.e.,T_(S)-T_(R),to infer the controlled product qualities.However,because the TDC scheme has failed to specially take the corresponding relationship between the TD employed in each control loop and the controlled product quality into account,it may suffer from relatively large steady-state errors in the controlled product qualities.To address this problem,an enhanced TDC(ETDC)scheme is proposed in the current article,in which an enhanced TD(ETD),i.e.,T_(S)-α×T_(R),is employed to replace the conventional TD for each control loop.While the locations of the sensitive and reference stages of the ETD are respectively determined according to sensitivity analysis and SVD analysis,the adjusted coefficientαis set to be the ratio between the averaged absolute variation magnitudes(AAVMs)of the T_(S)and T_(R)so that the relationship between the T_(S)and T_(R)can be appropriately coordinated.With reference to the operations of three different distillation systems,i.e.,one conventional DC distilling an ethanol(E)/butanol(B)binary mixture,one conventional DC distilling an E/propanol(P)/B ternary mixture,and one dividing-wall distillation column distilling an E/P/B ternary mixture,the performance of the ETDC scheme is assessed by compared with the conventional TDC scheme and the double TD control(DTDC)scheme.The dynamic simulation results show that the ETDC scheme is better than the conventional TDC scheme with reduced steady-state errors in the controlled product qualities and improved dynamic responses,and is comparable with the DTDC scheme despite the less temperature measurements are employed.展开更多
With the development of human society,the social hub enlarges beyond one community to the extent that the world is deemed as a community as a whole.Communication,therefore,plays an increasingly important role in our d...With the development of human society,the social hub enlarges beyond one community to the extent that the world is deemed as a community as a whole.Communication,therefore,plays an increasingly important role in our daily life.As a consequence,communication model or the definition of which is not so much a definition as a guide in communication.However,some existed communication models are not as practical as it was.This paper tries to make an overall contrast among three communication models——Coded Model,Gable's Communication Model and Ostensive Inferential Model,to see how they assist people to comprehend verbal and non-verbal communication.展开更多
The control of heat exchange stations in district heating system is critical for the overall energy efficiency and can be very difficult due to high level of complexity. A conventional method is to control the equipme...The control of heat exchange stations in district heating system is critical for the overall energy efficiency and can be very difficult due to high level of complexity. A conventional method is to control the equipment such that the temperature of hot water supply is maintained at a set-point that may be a fixed value or be compensated against the external temperature. This paper presents a novel scheme that can determine the optimal set-point of hot water supply that maximizes the energy efficiency whilst providing sufficient heating capacity to the load. This scheme is based on Adaptive Neuro-Fuzzy Inferential System. The aim of this study is to improve the overall performance of district heating systems.展开更多
These days when I look at scientific research papers or review manuscripts,there seems to be almost a competition to have a smaller p value as a means to present more significant findings.For example,a quick Internet ...These days when I look at scientific research papers or review manuscripts,there seems to be almost a competition to have a smaller p value as a means to present more significant findings.For example,a quick Internet search using"p〈0.0000001"turned up many papers even reporting their p values at this level.Can and should a smaller p value play such a role?In my opinion,it cannot.展开更多
Relevance theory belongs to the field of pragmatics. Translation is a kind of communicative activity in nature. In the frame of relevance theory, translation is the process of cognition and inference. This paper focus...Relevance theory belongs to the field of pragmatics. Translation is a kind of communicative activity in nature. In the frame of relevance theory, translation is the process of cognition and inference. This paper focuses on the study of translation process on the basis of relevance theory in order to improve the practice of translation.展开更多
Inference by exclusion is the ability to select a given option by excluding the others.When designed appropriately,tests of this ability can reveal choices that cannot be explained by associative processes.Over ...Inference by exclusion is the ability to select a given option by excluding the others.When designed appropriately,tests of this ability can reveal choices that cannot be explained by associative processes.Over the past decade,exclusion reasoning has been explored in several non-human taxonomic groups,including birds,mainly in Corvids and Parrots.To increase our understanding of the taxonomic distribution of exclusion reasoning and,therefore,its evolution,we investigated exclusion performances in red-tailed black cockatoos(Calyptorhynchus banksii),an Australian relative of the Goffin cockatoo(Cacatua goffini),using a food-finding task.Cockatoos were required to find a food item hidden in 1 of the 2 experimenter’s hands.Following training sessions in which they reliably selected the closed baited hand they had just been shown open,each individual was tested on 4 different conditions.Critical to demonstrating exclusion reasoning was the condition in which they were shown the empty hand and then offered a choice of both closed hands.The performance of all birds was above chance on all experimental conditions but not on an olfactory and/or cuing control condition.The results suggest that the birds might be able to infer by exclusion,although an explanation based on rule learning cannot be excluded.This first experiment in red-tailed black cockatoo highlights the potential of this species as a model to study avian cognition and paves the pathway for future investigations.展开更多
This paper presents, from a practical viewpoint accommodation in distillation columns. Addressing faults in an investigation of real-time actuator fault detection, propagation and industrial processes, coupled with th...This paper presents, from a practical viewpoint accommodation in distillation columns. Addressing faults in an investigation of real-time actuator fault detection, propagation and industrial processes, coupled with the growing demand for higher performance, improved safety and reliability necessitates implementation of less complex alternative control strategies in the events of malfunctions in actuators, sensors and or other system components. This work demonstrates frugality in the design and implementation of fault tolerant control system by integrating fault detection and diagnosis techniques with simple active restructurable feedback controllers and with backup feedback signals and switchable reference points to accommodate actuator fault in distillation columns based on a priori assessed control structures. A multivariate statistical process monitoring based fault detection and diagnosis technique through dynamic principal components analysis is integrated with one-point control or alternative control structure for prompt and effective fault detection, isolation and accommodation. The work also investigates effects of disturbances on fault propagation and detection. Specifically, the reflux and vapor boil-up control strategy used for a binary distillation column during normal operation is switched to one point control of the more valued product by utilizing the remaining healthy actuator. The proposed approach was implemented on two distillation processes: a simulated methanol-water separation column and the benchmark Shell standard heavy oil fractionation process to assess its effectiveness.展开更多
文摘The selection of context is not random but limited by linguistic communicators'cognitive environment.Sperber &Wilson propose a more persuasive inferential model on the basis of Grice's theory.They think language communication is a de ductive and inferential process in which the communicators deal with the information in the context,a set of assumptions,and finally infer the meaning.Since a discourse is the work of language and the product of the process of linguistic communication,the inferential model will also adapt to the discourse analysis.With the inferential model as its basic analyzing framework,this paper puts discourse in a dynamic communicative process to investigate how the discourse receiver selects the context to make the com munication succeed.
基金Supported by the National Natural Science Foundation of China(21376018,21576014,21676011,21808007,and 21878011)the Fundamental Research Funds for the Central Universities(ZY1837)China Postdoctoral Science Foundation(2017M620587)
文摘Temperature inferential control (TIC) is studied for a reactive distillation column with double reactive sections (RDC-DRSs) processing a hypothetical two-stage consecutive reversible reaction (A + B■C + D, C + B■E + D with αD > αB > αC > αA > αE). Because of the complicated dynamic behaviors, the controlled stages by sensitivity analysis lead to great steady-state deviations (SSDs) in top and bottom product purities. Since TIC involves considerably reduced settling times in comparison with direct composition control, small SSDs in product qualities correspond generally to small transient deviations (TDs) in product qualities. An objective function that measures SSDs in product qualities is formulated to represent the performance of a TIC system and an iterative procedure is devised to search for the best control configuration. The application of the procedure to the RDC-DRS gives considerably suppressed TDs and SSDs in top and bottom product qualities as compared with the one by sensitivity analysis. The method is simpler in principle and less computationally intensive than the current practice. These striking outcomes show the effectiveness of the proposed principle for the development of TIC systems for complicated reactive distillation columns.
基金Supported by the National Natural Science Foundation of China(21676299,21476261and 21606255)
文摘The dividing wall column (DWC) is considered as a major breakthrough in distillation technology and has good prospect of industrialization. Model predictive control (MPC) is an advanced control strategy that has acquired extensive applications in various industries. In this study, MPC is applied to the process for separating ethanol, n-propanol, and n-butanol ternary mixture in a fully thermally coupled DWC. Both composition control and tem- perature inferent/al control are considered. The multiobjective genetic algor/thm function "gamult/obj" in Matlab is used for the weight tuning of MPC. Comparisons are made between the control performances of MPC and PI strategies. Simulation results show that although both MPC and PI schemes can stabilize the DWC in case of feed disturbances, MPC generally behaves better than the PI strategy for both composition control and tempera- ture inferential control, resulting in a more stable and superior performance with lower values of integral of squared error (ISE).
文摘Inferential models are widely used in the chemical industry to infer key process variables, which are challenging or expensive to measure, from other more easily measured variables. The aim of this paper is three-fold: to present a theoretical review of some of the well known linear inferential modeling techniques, to enhance the predictive ability of the regularized canonical correlation analysis (RCCA) method, and finally to compare the performances of these techniques and highlight some of the practical issues that can affect their predictive abilities. The inferential modeling techniques considered in this study include full rank modeling techniques, such as ordinary least square (OLS) regression and ridge regression (RR), and latent variable regression (LVR) techniques, such as principal component regression (PCR), partial least squares (PLS) regression, and regularized canonical correlation analysis (RCCA). The theoretical analysis shows that the loading vectors used in LVR modeling can be computed by solving eigenvalue problems. Also, for the RCCA method, we show that by optimizing the regularization parameter, an improvement in prediction accuracy can be achieved over other modeling techniques. To illustrate the performances of all inferential modeling techniques, a comparative analysis was performed through two simulated examples, one using synthetic data and the other using simulated distillation column data. All techniques are optimized and compared by computing the cross validation mean square error using unseen testing data. The results of this comparative analysis show that scaling the data helps improve the performances of all modeling techniques, and that the LVR techniques outperform the full rank ones. One reason for this advantage is that the LVR techniques improve the conditioning of the model by discarding the latent variables (or principal components) with small eigenvalues, which also reduce the effect of the noise on the model prediction. The results also show that PCR and PLS have comparable performances, and that RCCA can provide an advantage by optimizing its regularization parameter.
基金This research is supported by National Natural Science Foundation of China(No.61902158).
文摘The inherent randomness,intermittence and volatility of wind power generation compromise the quality of the wind power system,resulting in uncertainty in the system’s optimal scheduling.As a result,it’s critical to improve power quality and assure real-time power grid scheduling and grid-connected wind farm operation.Inferred statistics are utilized in this research to infer general features based on the selected information,confirming that there are differences between two forecasting categories:Forecast Category 1(0-11 h ahead)and Forecast Category 2(12-23 h ahead).In z-tests,the null hypothesis provides the corresponding quantitative findings.To verify the final performance of the prediction findings,five benchmark methodologies are used:Persistence model,LMNN(Multilayer Perceptron with LMlearningmethods),NARX(Nonlinear autoregressive exogenous neural networkmodel),LMRNN(RNNs with LM training methods)and LSTM(Long short-term memory neural network).Experiments using a real dataset show that the LSTM network has the highest forecasting accuracy when compared to other benchmark approaches including persistence model,LMNN,NARX network,and LMRNN,and the 23-steps forecasting accuracy has improved by 19.61%.
基金Supported by the National High-Tech Development Program of China(No.863-511-920-011,2001AA411230).
文摘Multivariate statistical process monitoring and control (MSPM&C) methods for chemical process monitoring with statistical projection techniques such as principal component analysis (PCA) and partial least squares (PLS) are surveyed in this paper. The four-step procedure of performing MSPM&C for chemical process, modeling of processes, detecting abnormal events or faults, identifying the variable(s) responsible for the faults and diagnosing the source cause for the abnormal behavior, is analyzed. Several main research directions of MSPM&C reported in the literature are discussed, such as multi-way principal component analysis (MPCA) for batch process, statistical monitoring and control for nonlinear process, dynamic PCA and dynamic PLS, and on-line quality control by inferential models. Industrial applications of MSPM&C to several typical chemical processes, such as chemical reactor, distillation column, polymerization process, petroleum refinery units, are summarized. Finally, some concluding remarks and future considerations are made.
基金supported by the Chemical Engineering Department at the University of Waterloo。
文摘A latent variable regression algorithm with a regularization term(r LVR) is proposed in this paper to extract latent relations between process data X and quality data Y. In rLVR,the prediction error between X and Y is minimized, which is proved to be equivalent to maximizing the projection of quality variables in the latent space. The geometric properties and model relations of rLVR are analyzed, and the geometric and theoretical relations among r LVR, partial least squares, and canonical correlation analysis are also presented. The rLVR-based monitoring framework is developed to monitor process-relevant and quality-relevant variations simultaneously. The prediction and monitoring effectiveness of rLVR algorithm is demonstrated through both numerical simulations and the Tennessee Eastman(TE) process.
基金the Korea Research Foundation Grant Funded by the Korean Government (MOEHRD) (KRF-2007-331-D00089) Funded by Seoul Development Institute (CS070160)
文摘A new on-line predictive monitoring and prediction model for periodic biological processes is proposed using the multiway non-Gaussian modeling. The basic idea of this approach is to use multiway non-Gaussian modeling to extract some dominant key components from daily normal operation data in a periodic process, and subsequently combining these components with predictive statistical process monitoring techniques. The proposed predictive monitoring method has been applied to fault detection and diagnosis in the biological wastewater-treatment process, which is based on strong diurnal characteristics. The results show the power and advantages of the proposed predictive monitoring of a continuous process using the multiway predictive monitoring concept, which is thus able to give very useful conceptual results for a daily monitoring process and also enables a more rapid detection of the process fault than other traditional monitoring methods.
文摘A maximum test in lieu of forcing a choice between the two dependent samples t-test and Wilcoxon signed-ranks test is proposed. The maximum test, which requires a new table of critical values, maintains nominal α while guaranteeing the maximum power of the two constituent tests. Critical values, obtained via Monte Carlo methods, are uniformly smaller than the Bonferroni-Dunn adjustment, giving it power superiority when testing for treatment alternatives of shift in location parameter when data are sampled from non-normal distributions.
基金China Postdoctoral Science Foundation(No.2019M650453)Fundamental Research Funds for the Central Universities(ZY1930)+1 种基金National Natural Science Foundation of China(21808007,21878011,21676011,and 21576014)Open Foundation of State Key Laboratory of Chemical Engineering(No.SKL-ChE-18B01)。
文摘Temperature difference control(TDC)schemes can clearly suppress the adverse influence of pressure variations on product quality control of various distillation columns(DCs)by employing temperature differences(TDs)between the sensitive stage temperature(T_(S))and reference stage temperature(T_(R)),i.e.,T_(S)-T_(R),to infer the controlled product qualities.However,because the TDC scheme has failed to specially take the corresponding relationship between the TD employed in each control loop and the controlled product quality into account,it may suffer from relatively large steady-state errors in the controlled product qualities.To address this problem,an enhanced TDC(ETDC)scheme is proposed in the current article,in which an enhanced TD(ETD),i.e.,T_(S)-α×T_(R),is employed to replace the conventional TD for each control loop.While the locations of the sensitive and reference stages of the ETD are respectively determined according to sensitivity analysis and SVD analysis,the adjusted coefficientαis set to be the ratio between the averaged absolute variation magnitudes(AAVMs)of the T_(S)and T_(R)so that the relationship between the T_(S)and T_(R)can be appropriately coordinated.With reference to the operations of three different distillation systems,i.e.,one conventional DC distilling an ethanol(E)/butanol(B)binary mixture,one conventional DC distilling an E/propanol(P)/B ternary mixture,and one dividing-wall distillation column distilling an E/P/B ternary mixture,the performance of the ETDC scheme is assessed by compared with the conventional TDC scheme and the double TD control(DTDC)scheme.The dynamic simulation results show that the ETDC scheme is better than the conventional TDC scheme with reduced steady-state errors in the controlled product qualities and improved dynamic responses,and is comparable with the DTDC scheme despite the less temperature measurements are employed.
文摘With the development of human society,the social hub enlarges beyond one community to the extent that the world is deemed as a community as a whole.Communication,therefore,plays an increasingly important role in our daily life.As a consequence,communication model or the definition of which is not so much a definition as a guide in communication.However,some existed communication models are not as practical as it was.This paper tries to make an overall contrast among three communication models——Coded Model,Gable's Communication Model and Ostensive Inferential Model,to see how they assist people to comprehend verbal and non-verbal communication.
文摘The control of heat exchange stations in district heating system is critical for the overall energy efficiency and can be very difficult due to high level of complexity. A conventional method is to control the equipment such that the temperature of hot water supply is maintained at a set-point that may be a fixed value or be compensated against the external temperature. This paper presents a novel scheme that can determine the optimal set-point of hot water supply that maximizes the energy efficiency whilst providing sufficient heating capacity to the load. This scheme is based on Adaptive Neuro-Fuzzy Inferential System. The aim of this study is to improve the overall performance of district heating systems.
文摘These days when I look at scientific research papers or review manuscripts,there seems to be almost a competition to have a smaller p value as a means to present more significant findings.For example,a quick Internet search using"p〈0.0000001"turned up many papers even reporting their p values at this level.Can and should a smaller p value play such a role?In my opinion,it cannot.
文摘Relevance theory belongs to the field of pragmatics. Translation is a kind of communicative activity in nature. In the frame of relevance theory, translation is the process of cognition and inference. This paper focuses on the study of translation process on the basis of relevance theory in order to improve the practice of translation.
文摘Inference by exclusion is the ability to select a given option by excluding the others.When designed appropriately,tests of this ability can reveal choices that cannot be explained by associative processes.Over the past decade,exclusion reasoning has been explored in several non-human taxonomic groups,including birds,mainly in Corvids and Parrots.To increase our understanding of the taxonomic distribution of exclusion reasoning and,therefore,its evolution,we investigated exclusion performances in red-tailed black cockatoos(Calyptorhynchus banksii),an Australian relative of the Goffin cockatoo(Cacatua goffini),using a food-finding task.Cockatoos were required to find a food item hidden in 1 of the 2 experimenter’s hands.Following training sessions in which they reliably selected the closed baited hand they had just been shown open,each individual was tested on 4 different conditions.Critical to demonstrating exclusion reasoning was the condition in which they were shown the empty hand and then offered a choice of both closed hands.The performance of all birds was above chance on all experimental conditions but not on an olfactory and/or cuing control condition.The results suggest that the birds might be able to infer by exclusion,although an explanation based on rule learning cannot be excluded.This first experiment in red-tailed black cockatoo highlights the potential of this species as a model to study avian cognition and paves the pathway for future investigations.
基金supported by the EU FP7(No.PIRSES-GA-2013-612230)
文摘This paper presents, from a practical viewpoint accommodation in distillation columns. Addressing faults in an investigation of real-time actuator fault detection, propagation and industrial processes, coupled with the growing demand for higher performance, improved safety and reliability necessitates implementation of less complex alternative control strategies in the events of malfunctions in actuators, sensors and or other system components. This work demonstrates frugality in the design and implementation of fault tolerant control system by integrating fault detection and diagnosis techniques with simple active restructurable feedback controllers and with backup feedback signals and switchable reference points to accommodate actuator fault in distillation columns based on a priori assessed control structures. A multivariate statistical process monitoring based fault detection and diagnosis technique through dynamic principal components analysis is integrated with one-point control or alternative control structure for prompt and effective fault detection, isolation and accommodation. The work also investigates effects of disturbances on fault propagation and detection. Specifically, the reflux and vapor boil-up control strategy used for a binary distillation column during normal operation is switched to one point control of the more valued product by utilizing the remaining healthy actuator. The proposed approach was implemented on two distillation processes: a simulated methanol-water separation column and the benchmark Shell standard heavy oil fractionation process to assess its effectiveness.