Based on a nonlinear state predictor (NSP) and a strong tracking filter (STF), a sensor fault tolerant generic model control (FTGMC) approach for a class of nonlinear time-delay processes is proposed. First, the NSP i...Based on a nonlinear state predictor (NSP) and a strong tracking filter (STF), a sensor fault tolerant generic model control (FTGMC) approach for a class of nonlinear time-delay processes is proposed. First, the NSP is introduced, and it is used to extend the conventional generic model control (GMC) to nonlinear processes with large input time-delay. Then the STF is adopted to estimate process states and sensor bias, the estimated sensor bias is used to drive a fault detection logic. When a sensor fault is detected, the estimated process states by the STF will be used to construct the process output to form a 'soft sensor', which is then used by the NSP (instead of the real outputs) to provide state predictors. These procedures constitute an active fault tolerant control scheme. Finally, simulation results of a three-tank-system demonstrate the effectiveness of the proposed approach.展开更多
Turbulent forced convective heat transfer and flow con figurations in a square channel with wavy-ribs inserted diagonally are examined numerically. The in fluences of the 30° and 45° flow attack angles for w...Turbulent forced convective heat transfer and flow con figurations in a square channel with wavy-ribs inserted diagonally are examined numerically. The in fluences of the 30° and 45° flow attack angles for wavy-ribs, blockage ratio, R B= b/H = 0.05–0.25 with single pitch ratio, R P= P/H = 1 are investigated for the Reynolds number based on the hydraulic diameter of the square channel, Re = 3000–20000. The use of the wavy-ribs, which inserted diagonal in the square channel, is aimed to help to improve the thermal performance in heat exchange systems.The finite volume method and SIMPLE algorithm are applied to the present numerical simulation. The results are presented on the periodic flow and heat transfer pro files, flow con figurations, heat transfer characteristics and the performance evaluations. The mathematical results reveal that the use of wavy-ribs leads to a higher heat transfer rate and friction loss over the smooth channel. The heat transfer enhancements are around 1.97–5.14 and 2.04–5.27 times over the smooth channel for 30° and 45° attack angles, respectively. However, the corresponding friction loss values for 30° and 45° are around 4.26–86.55 and 5.03–97.98 times higher than the smooth square channel, respectively. The optimum thermal enhancement factor on both cases is found at R B= 0.10 and the lowest Reynolds number, Re = 3000, to be about 1.47 and 1.52, respectively, for 30° and 45° wavy-ribs.展开更多
The health care sector is the most difficult one to manage and control. Special units in this field are public hospitals which are required to prepare a lot of reports to various institutions, including the ownership ...The health care sector is the most difficult one to manage and control. Special units in this field are public hospitals which are required to prepare a lot of reports to various institutions, including the ownership body. The paper focuses on two issues. The first is the presence of behavioral factors in the reporting of public hospitals in Poland to the ownership bodies. This article aims to indicate the thematic areas of specific reports, most affected by behavioral factors and explain the causes and consequences of their occurrence. The second issue is the analysis of the legal status of obligatory reporting of public hospitals. Participants of the conducted research, due to their specific ownership and political and social position, were public hospitals in Poland. The paper uses the research methods of the meta-analysis of the literature, legal acts in Poland and empirical materials, and also the methods of synthesis, observation, and deduction. Data analysis focused on specific sample of reports issued by Polish public hospitals for their ownership body. The research shows that hospitals draw up a tremendous number of often thematically overlapping and redundant reports addressed to different institutions in different time periods. It is a consequence of legal regulations failing to streamline the reporting of the health care sector institutions, in particular public hospitals. The paper points to the large number of legal instruments that contain imprecise requirements resulting from the complex and obscure forms of control of public funds allocation in this sector. There are many behavioral factors that shape some fields of public hospitals＇ reports, for example, interpersonal relationships, egoism, private financial interests, strengthening of the employment status and professional position, and professional competences. There is considerable freedom in the reporting process fulfilled by public hospitals in Poland for their ownership body. It causes strong consequences, like poor-quality data, duplication of information, and its chaos, as well as high costs of obtaining information. Reporting system of financial and non-financial data of public hospitals in Poland is dysfunctional.展开更多
Strong, normal shock wave, terminating a local supersonic area on an airfoil, not only limits aerodynamic performance but also becomes a source of a high-speed impulsive helicopter noise. The application of a passive ...Strong, normal shock wave, terminating a local supersonic area on an airfoil, not only limits aerodynamic performance but also becomes a source of a high-speed impulsive helicopter noise. The application of a passive control system （a cavity covered by a perforated plate） on a rotor blade should reduce the noise created by a moving shock. This article covers the numerical implementation of the Bohning/Doerffer transpiration law into the SPARC code and includes an extended validation against the experimental data for relatively simple geometries of transonic nozzles. It is a first step towards a full simulation of a helicopter rotor equipped with a noise reducing passive control device in hover and in forward flight conditions.展开更多
A boundary element method has been developed for analysing heat transport phenomena in solitary wave on falling thin liquid films at high Reynolds numbers. The divergence theorem is applied to the non-linear convectiv...A boundary element method has been developed for analysing heat transport phenomena in solitary wave on falling thin liquid films at high Reynolds numbers. The divergence theorem is applied to the non-linear convective volume integral of the boundary element formulation with the pressure penalty function. Consequently, velocity and temperature gradients are eliminated, and the complete formulation is written in terms of velocity and temperature. This provides considerable reduction in storage and computational requirements while improving accuracy. The non-linear equation systems of boundary element discretization are solved by the quasi-Newton iterative scheme with Broyden's update. The streamline maps and the temperature distributions in solitary wave and wavy film flow have been obtained, and the variations of Nusselt numbers along the wall-liquid interface are also given. There are large cross-flow velocities and S-shape temperature distributions in the recirculating region of solitary wave. This special flow and thermal process can be a mechanism to enhance heat transport.展开更多
The time-dependent analysis of four-wave mixing(FWM) has been performed in four-level double semiconductor quantum wells(SQWs) considering the cross-coupling of the longitude-optical phonons(LOP) relaxation. It is sho...The time-dependent analysis of four-wave mixing(FWM) has been performed in four-level double semiconductor quantum wells(SQWs) considering the cross-coupling of the longitude-optical phonons(LOP) relaxation. It is shown that both the amplitude and the conversion efficiency of the FWM field enhance greatly with the increasing strength of cross-coupling of LOP relaxation. Interestingly, a double peak value of the conversion efficiency is obtained under a relatively weak single-photon detuning considering the LOP coupling. When the detuning becomes stronger,the double peaks turn into one peak appearing at the line respect to the about equality two control fields. The results can be interpreted by the effect of electromagnetically induced transparency and the indirect transition. Such controlled high efficiency FWM based on the cross-coupling LOP may have potential applications in quantum control and communications.展开更多
基金Supported by the National Natural Science Foundation of China (No. 60025307, No. 60234010) the National 863 Project(No. 2001AA413130,2002AA412420)+1 种基金 Research Fund for the Doctoral Program of Higher Education (No. 20020003063) the National 973 Program
文摘Based on a nonlinear state predictor (NSP) and a strong tracking filter (STF), a sensor fault tolerant generic model control (FTGMC) approach for a class of nonlinear time-delay processes is proposed. First, the NSP is introduced, and it is used to extend the conventional generic model control (GMC) to nonlinear processes with large input time-delay. Then the STF is adopted to estimate process states and sensor bias, the estimated sensor bias is used to drive a fault detection logic. When a sensor fault is detected, the estimated process states by the STF will be used to construct the process output to form a 'soft sensor', which is then used by the NSP (instead of the real outputs) to provide state predictors. These procedures constitute an active fault tolerant control scheme. Finally, simulation results of a three-tank-system demonstrate the effectiveness of the proposed approach.
基金Supported by College of Industrial Technology,King Mongkut's University of Technology North Bangkok,Thailand
文摘Turbulent forced convective heat transfer and flow con figurations in a square channel with wavy-ribs inserted diagonally are examined numerically. The in fluences of the 30° and 45° flow attack angles for wavy-ribs, blockage ratio, R B= b/H = 0.05–0.25 with single pitch ratio, R P= P/H = 1 are investigated for the Reynolds number based on the hydraulic diameter of the square channel, Re = 3000–20000. The use of the wavy-ribs, which inserted diagonal in the square channel, is aimed to help to improve the thermal performance in heat exchange systems.The finite volume method and SIMPLE algorithm are applied to the present numerical simulation. The results are presented on the periodic flow and heat transfer pro files, flow con figurations, heat transfer characteristics and the performance evaluations. The mathematical results reveal that the use of wavy-ribs leads to a higher heat transfer rate and friction loss over the smooth channel. The heat transfer enhancements are around 1.97–5.14 and 2.04–5.27 times over the smooth channel for 30° and 45° attack angles, respectively. However, the corresponding friction loss values for 30° and 45° are around 4.26–86.55 and 5.03–97.98 times higher than the smooth square channel, respectively. The optimum thermal enhancement factor on both cases is found at R B= 0.10 and the lowest Reynolds number, Re = 3000, to be about 1.47 and 1.52, respectively, for 30° and 45° wavy-ribs.
文摘The health care sector is the most difficult one to manage and control. Special units in this field are public hospitals which are required to prepare a lot of reports to various institutions, including the ownership body. The paper focuses on two issues. The first is the presence of behavioral factors in the reporting of public hospitals in Poland to the ownership bodies. This article aims to indicate the thematic areas of specific reports, most affected by behavioral factors and explain the causes and consequences of their occurrence. The second issue is the analysis of the legal status of obligatory reporting of public hospitals. Participants of the conducted research, due to their specific ownership and political and social position, were public hospitals in Poland. The paper uses the research methods of the meta-analysis of the literature, legal acts in Poland and empirical materials, and also the methods of synthesis, observation, and deduction. Data analysis focused on specific sample of reports issued by Polish public hospitals for their ownership body. The research shows that hospitals draw up a tremendous number of often thematically overlapping and redundant reports addressed to different institutions in different time periods. It is a consequence of legal regulations failing to streamline the reporting of the health care sector institutions, in particular public hospitals. The paper points to the large number of legal instruments that contain imprecise requirements resulting from the complex and obscure forms of control of public funds allocation in this sector. There are many behavioral factors that shape some fields of public hospitals＇ reports, for example, interpersonal relationships, egoism, private financial interests, strengthening of the employment status and professional position, and professional competences. There is considerable freedom in the reporting process fulfilled by public hospitals in Poland for their ownership body. It causes strong consequences, like poor-quality data, duplication of information, and its chaos, as well as high costs of obtaining information. Reporting system of financial and non-financial data of public hospitals in Poland is dysfunctional.
文摘Strong, normal shock wave, terminating a local supersonic area on an airfoil, not only limits aerodynamic performance but also becomes a source of a high-speed impulsive helicopter noise. The application of a passive control system （a cavity covered by a perforated plate） on a rotor blade should reduce the noise created by a moving shock. This article covers the numerical implementation of the Bohning/Doerffer transpiration law into the SPARC code and includes an extended validation against the experimental data for relatively simple geometries of transonic nozzles. It is a first step towards a full simulation of a helicopter rotor equipped with a noise reducing passive control device in hover and in forward flight conditions.
基金This project was financially supported by the National Natural Science Foundation of China
文摘A boundary element method has been developed for analysing heat transport phenomena in solitary wave on falling thin liquid films at high Reynolds numbers. The divergence theorem is applied to the non-linear convective volume integral of the boundary element formulation with the pressure penalty function. Consequently, velocity and temperature gradients are eliminated, and the complete formulation is written in terms of velocity and temperature. This provides considerable reduction in storage and computational requirements while improving accuracy. The non-linear equation systems of boundary element discretization are solved by the quasi-Newton iterative scheme with Broyden's update. The streamline maps and the temperature distributions in solitary wave and wavy film flow have been obtained, and the variations of Nusselt numbers along the wall-liquid interface are also given. There are large cross-flow velocities and S-shape temperature distributions in the recirculating region of solitary wave. This special flow and thermal process can be a mechanism to enhance heat transport.
基金Supported by Program for Changjiang Scholars and Innovative Research Team in University under Grant(IRT1080)National Natural Science Foundation of China under Grant Nos.51272158,11374252,and 51372214+2 种基金Changjiang Scholar Incentive Program under Grant No.[2009]17Scientific Research Fund of Hunan Provincial Education Department of China under Grant No.12A140the Science and Technology Foundation of Guizhou Province of China under Grant No.J20122314
文摘The time-dependent analysis of four-wave mixing(FWM) has been performed in four-level double semiconductor quantum wells(SQWs) considering the cross-coupling of the longitude-optical phonons(LOP) relaxation. It is shown that both the amplitude and the conversion efficiency of the FWM field enhance greatly with the increasing strength of cross-coupling of LOP relaxation. Interestingly, a double peak value of the conversion efficiency is obtained under a relatively weak single-photon detuning considering the LOP coupling. When the detuning becomes stronger,the double peaks turn into one peak appearing at the line respect to the about equality two control fields. The results can be interpreted by the effect of electromagnetically induced transparency and the indirect transition. Such controlled high efficiency FWM based on the cross-coupling LOP may have potential applications in quantum control and communications.
