In this note,new classes of generalized type-I functions are introduced for functions between Banach spaces.These generalized type-I functions are then utilized to establish sufficient optimality conditions and dualit...In this note,new classes of generalized type-I functions are introduced for functions between Banach spaces.These generalized type-I functions are then utilized to establish sufficient optimality conditions and duality results for a vector optimization problem with functions defined on a Banach space.展开更多
This study addresses the adaptive control and function projective synchronization problems between 2D Rulkov discrete-time system and Network discrete-time system. Based on backstepping design with three controllers, ...This study addresses the adaptive control and function projective synchronization problems between 2D Rulkov discrete-time system and Network discrete-time system. Based on backstepping design with three controllers, a systematic, concrete and automatic scheme is developed to investigate the function projective synchronization of discretetime chaotic systems. In addition, the adaptive control function is applied to achieve the state synchronization of two discrete-time systems. Numerical results demonstrate the effectiveness of the proposed control scheme.展开更多
Feature-based image matching algorithms play an indispensable role in automatic target recognition (ATR). In this work, a fast image matching algorithm (FIMA) is proposed which utilizes the geometry feature of ext...Feature-based image matching algorithms play an indispensable role in automatic target recognition (ATR). In this work, a fast image matching algorithm (FIMA) is proposed which utilizes the geometry feature of extended centroid (EC) to build affine invariants. Based on at-fine invariants of the length ratio of two parallel line segments, FIMA overcomes the invalidation problem of the state-of-the-art algorithms based on affine geometry features, and increases the feature diversity of different targets, thus reducing misjudgment rate during recognizing targets. However, it is found that FIMA suffers from the parallelogram contour problem and the coincidence invalidation. An advanced FIMA is designed to cope with these problems. Experiments prove that the proposed algorithms have better robustness for Gaussian noise, gray-scale change, contrast change, illumination and small three-dimensional rotation. Compared with the latest fast image matching algorithms based on geometry features, FIMA reaches the speedup of approximate 1.75 times. Thus, FIMA would be more suitable for actual ATR applications.展开更多
In order to overcome the inherent oscillation problem of potential field methods(PFMs) for autonomous mobile robots in the presence of obstacles and in narrow passages,an enhanced potential field method that integrate...In order to overcome the inherent oscillation problem of potential field methods(PFMs) for autonomous mobile robots in the presence of obstacles and in narrow passages,an enhanced potential field method that integrates Levenberg-Marquardt(L-M) algorithm and k-trajectory algorithm into the basic PFMs is proposed and simulated.At first,the mobile robot navigation function based on the basic PFMs is established by choosing Gaussian model.Then,the oscillation problem of the navigation function is investigated when a mobile robot nears obstacles and passes through a long and narrow passage,which can cause large computation cost and system instability.At last,the L-M algorithm is adopted to modify the search direction of the navigation function for alleviating the oscillation,while the k-trajectory algorithm is applied to further smooth trajectories.By a series of comparative experiments,the use of the L-M algorithm and k-trajectory algorithm can greatly improve the system performance with the advantages of reducing task completion time and achieving smooth trajectories.展开更多
The construction of Grain Production Functional Zone and Modern Agicultural Zone (Two Zones for short) plays a key role in the development of modern agriculture and solving the quantity and quality problems of agric...The construction of Grain Production Functional Zone and Modern Agicultural Zone (Two Zones for short) plays a key role in the development of modern agriculture and solving the quantity and quality problems of agricultural products. The Two Zones serves as the important form and carrier of agricultural standardization and the agricultural standardization provides means and ways for it. The paper puts forward the suggestions and solutions for agricultural standardization in Two Zones in the aspects of boosting standards innovation projects, management and so forth.展开更多
The generalized complementarity problem includes the well-known nonlinear complementarity problem and linear complementarity problem as special cases.In this paper, based on a class of smoothing functions, a smoothing...The generalized complementarity problem includes the well-known nonlinear complementarity problem and linear complementarity problem as special cases.In this paper, based on a class of smoothing functions, a smoothing Newton-type algorithm is proposed for solving the generalized complementarity problem.Under suitable assumptions, the proposed algorithm is well-defined and global convergent.展开更多
A self-adaptive learning based immune algorithm (SALIA) is proposed to tackle diverse optimization problems, such as complex multi-modal and ill-conditioned prc,blems with the high robustness. The SALIA algorithm ad...A self-adaptive learning based immune algorithm (SALIA) is proposed to tackle diverse optimization problems, such as complex multi-modal and ill-conditioned prc,blems with the high robustness. The SALIA algorithm adopted a mutation strategy pool which consists of four effective mutation strategies to generate new antibodies. A self-adaptive learning framework is implemented to select the mutation strategies by learning from their previous performances in generating promising solutions. Twenty-six state-of-the-art optimization problems with different characteristics, such as uni-modality, multi-modality, rotation, ill-condition, mis-scale and noise, are used to verify the validity of SALIA. Experimental results show that the novel algorithm SALIA achieves a higher universality and robustness than clonal selection algorithms (CLONALG), and the mean error index of each test function in SALIA decreases by a factor of at least 1.0×10^7 in average.展开更多
Recent research has showed increasing interest at the vital role of irrigation ponds that plays at biodiversity conservation,and provides ecological functions at a wide range.However,many irrigation ponds were abolish...Recent research has showed increasing interest at the vital role of irrigation ponds that plays at biodiversity conservation,and provides ecological functions at a wide range.However,many irrigation ponds were abolished due to the economic and societal transformation in the rural.In particular,small-scale ponds were abolished and rebuilt to other public uses based on the consensus building process among the community.At the same time,civil organizations also launched initiatives to conserve irrigation ponds for its ecological significance or landscape scenery.However,study pertinent to the small scale ponds in the rural setting is largely neglected.This research aims at revealing the current situation of the utilization and management of small irrigation ponds using a case study of Noto Island in Ishikawa Prefecture.It was found that irrigation ponds are still under the traditional co-management of rural community.The most important finding in this study is that the traditional management of pond water use largely contributes to mitigate the harvest loss from natural disasters such as drought in the face of extreme climate.However,irrigation ponds are facing the threat of degradation due to the sharp decrease of farm population and the existing large number of part time farmers.Therefore,the small scale irrigation ponds and pertinent management and water use allotment should be revalued for its functions at a wide range from the biological and ecological functions and human knowledge system to mitigate disaster threats.展开更多
This paper proposes a global topology optimization algorithm based on subset simulation for the singular optimum problem subject to stress constraints of trusses. The constraints are handled by a fitness function whic...This paper proposes a global topology optimization algorithm based on subset simulation for the singular optimum problem subject to stress constraints of trusses. The constraints are handled by a fitness function which reflects their degree of violation. The rational and global topology results are guaranteed by the judgment of the samples’ rationality and the Metropolis-Hasting algorithm. Three examples show that the established method can quickly reduce the searching region to the feasible region and converge to the global optimum precisely enough for the singular optimum problem.展开更多
In this paper, we propose a new smooth function that possesses a property not satisfied by the existing smooth functions. Based on this smooth function, we discuss the existence and continuity of the smoothing path fo...In this paper, we propose a new smooth function that possesses a property not satisfied by the existing smooth functions. Based on this smooth function, we discuss the existence and continuity of the smoothing path for solving the P0 function nonlinear complementarity problem (NCP). Using the characteristics of the new smooth function, we investigate the boundedness of the iteration sequence generated by the non-interior continuation methods for solving the P0 function NCP under the assumption that the solution set of the NCP is nonempty and bounded. We show that the assumption that the solution set of the NCP is nonempty and bounded is weaker than those required by a few existing continuation methods for solving the NCP.展开更多
This paper presents a novel analysis for the solution of nonlinear age-structured prob- lem which is of extreme importance in biological sciences. The presented model is very useful but quite complicated. Modified var...This paper presents a novel analysis for the solution of nonlinear age-structured prob- lem which is of extreme importance in biological sciences. The presented model is very useful but quite complicated. Modified variational iteration method (MVIM) coupled with auxiliary parameter is used to cope with the complexity of the model which subse- quently shows better results as compared to some existing results available in literature. Furthermore, an appropriate way is used for the identification of auxiliary parameter by means of residual function. Numerical examples are presented for the analysis of the pro- posed algorithm. Graphical results along with the discussions re-confirm the efficiency of proposed algorithm. The work proposes a new algorithm where He's polynomials and an auxiliary parameter are merged with correction functional. The suggested scheme is implemented on nonlinear age-structured population models. Graphs are plotted for the residual function that reflects the accuracy and convergence of the presented algorithm.展开更多
Wound healing has invariably been a fundamental health concern,demanding manpower and materials and causing financial burdens.In this research,inspired by the hemostatic function of platelets,we proposed a novel bioni...Wound healing has invariably been a fundamental health concern,demanding manpower and materials and causing financial burdens.In this research,inspired by the hemostatic function of platelets,we proposed a novel bionic hydrogel by covalent amidation crosslinking natural platelet and alginate for wound healing.With the natural functional groups,the platelet-derived hydrogel exhibited outstanding biocompatibility and blood compatibility.By changing the addition ratio of platelets to alginates,the mechanical properties of the achieved hydrogel were variable to cater to different wound environments.Furthermore,silver nanoparticles could be loaded into the void space of the hydrogel which endowed the composites with superior anti-infective properties.We have demonstrated that the bio-inspired platelet hydrogel could promote hemostasis of acute tissue damage,prevent bacterial proliferation,and promote angiogenesis,collagen deposition,and granulation tissue formation in wound healing.These features signify the potential values of the bio-inspired platelet hydrogel in clinical applications.展开更多
This paper deals with the standing wave for a Hamiltonian nonlinear wave equation which can be viewed as a representative of the class of equations of interest.On the one hand,by proving a compactness lemma and solvin...This paper deals with the standing wave for a Hamiltonian nonlinear wave equation which can be viewed as a representative of the class of equations of interest.On the one hand,by proving a compactness lemma and solving a variational problem,the existence of the standing wave with ground state for the aforementioned equation is proved.On the other hand,the authors derive the instability of the standing wave by applying the potential well argument,the concavity method and an invariant region under the solution flow of the Cauchy problem for the equation under study,and the invariance of the region aforementioned can be shown by introducing an auxiliary functional and a supplementary constrained variational problem.展开更多
The inverter-fed motor is a key component of environmental-friendly hybrid cars, high-speed trains, and other industrial applications. After the widespread use of inverter-fed motors, the repetitive impulse surges fro...The inverter-fed motor is a key component of environmental-friendly hybrid cars, high-speed trains, and other industrial applications. After the widespread use of inverter-fed motors, the repetitive impulse surges from inverters were found to cause new insulation problems in inverter-fed motors that were linked to premature insulation failure. The partial discharge (PD) induced by the overvoltage inner stator windings was found to be the root cause of insulation reliability problems. To mitigate this problem, PD detection and life testing at repetitive square voltages should be performed on new types of insulation models and entire motor insulation systems. The obtained partial discharge inception voltage (PDIV) and lifetime of insulation in the tests can be used to evaluate the insulation status of inverter-fed motor insulation systems and thus to improve the insulation designs. At AC voltage conditions, the voltage frequency can significantly affect PD activity. At repetitive square voltage with rapid rise time, the influence of the square voltage frequency on PD activity should be investigated (1) to suggest values for the repetitive square voltage frequency selection for the PDIV and lifetime tests, and (2) to increase the signal-to-noise ratio when extracting PD pulses from strong disturbances generated by the operating switch of impulse generators. Therefore, the main purpose of this paper was to investigate the effects of repetitive square voltage frequency on PD events. Insulation models of both Type I (low-voltage inverter-fed motor) and Type II (high-voltage inverter-fed motor) were used to obtain single-PD and multi-PD statistical features, respectively. Experimental results indicated that higher frequencies caused less PD events with lower PD magnitudes and shorter delay times in one square voltage cycle. This phenomenon was attributed to the different surface charge decay ratios and the initial electron emission probabilities resulting from different square voltage frequencies. Finally, a number of considerations for PD measurements on inverter-fed motors were provided to improve the sensitivity of the PD test system and to obtain high objective insulation lifetime test results, which are used to assess the insulation status of inverter-fed motors.展开更多
We consider the nearest-neighbor model on the finite tree T with generator L. We obtain a twosided estimate of the spectral gap by factor 2. We also identify explicitly the Lipschitzian norm of the operator(-L)^(-1) i...We consider the nearest-neighbor model on the finite tree T with generator L. We obtain a twosided estimate of the spectral gap by factor 2. We also identify explicitly the Lipschitzian norm of the operator(-L)^(-1) in propriate functional space. This leads to the identification of the best constant in the generalized Cheeger isoperimetric inequality on the tree, and to transportation-information inequalities.展开更多
基金Foundation item: Supported by the National Natural Science Foundation of China(60574075) University, engaged in optimization theory and application.
文摘In this note,new classes of generalized type-I functions are introduced for functions between Banach spaces.These generalized type-I functions are then utilized to establish sufficient optimality conditions and duality results for a vector optimization problem with functions defined on a Banach space.
基金supported by the Natural Science Foundation of China under Grant Nos.10747141 and 10735030Zhejiang Provincial Natural Science Foundation under Grant No.605408+3 种基金Ningbo Natural Science Foundation under Grant Nos.2007A610049 and 2008A61001National Basic Research Program of China (973 Program 2007CB814800)Programme for Changjiang Scholars and Innovative Research Team in University (IRT0734)K.C.Wong Magna Fund in Ningbo University
文摘This study addresses the adaptive control and function projective synchronization problems between 2D Rulkov discrete-time system and Network discrete-time system. Based on backstepping design with three controllers, a systematic, concrete and automatic scheme is developed to investigate the function projective synchronization of discretetime chaotic systems. In addition, the adaptive control function is applied to achieve the state synchronization of two discrete-time systems. Numerical results demonstrate the effectiveness of the proposed control scheme.
基金Projects(2012AA010901,2012AA01A301)supported by National High Technology Research and Development Program of ChinaProjects(61272142,61103082,61003075,61170261,61103193)supported by the National Natural Science Foundation of ChinaProjects(B120601,CX2012A002)supported by Fund Sponsor Project of Excellent Postgraduate Student of NUDT,China
文摘Feature-based image matching algorithms play an indispensable role in automatic target recognition (ATR). In this work, a fast image matching algorithm (FIMA) is proposed which utilizes the geometry feature of extended centroid (EC) to build affine invariants. Based on at-fine invariants of the length ratio of two parallel line segments, FIMA overcomes the invalidation problem of the state-of-the-art algorithms based on affine geometry features, and increases the feature diversity of different targets, thus reducing misjudgment rate during recognizing targets. However, it is found that FIMA suffers from the parallelogram contour problem and the coincidence invalidation. An advanced FIMA is designed to cope with these problems. Experiments prove that the proposed algorithms have better robustness for Gaussian noise, gray-scale change, contrast change, illumination and small three-dimensional rotation. Compared with the latest fast image matching algorithms based on geometry features, FIMA reaches the speedup of approximate 1.75 times. Thus, FIMA would be more suitable for actual ATR applications.
基金Supported by the National Key Basic Research Program of China(973 Project)(No.2013CB035503)
文摘In order to overcome the inherent oscillation problem of potential field methods(PFMs) for autonomous mobile robots in the presence of obstacles and in narrow passages,an enhanced potential field method that integrates Levenberg-Marquardt(L-M) algorithm and k-trajectory algorithm into the basic PFMs is proposed and simulated.At first,the mobile robot navigation function based on the basic PFMs is established by choosing Gaussian model.Then,the oscillation problem of the navigation function is investigated when a mobile robot nears obstacles and passes through a long and narrow passage,which can cause large computation cost and system instability.At last,the L-M algorithm is adopted to modify the search direction of the navigation function for alleviating the oscillation,while the k-trajectory algorithm is applied to further smooth trajectories.By a series of comparative experiments,the use of the L-M algorithm and k-trajectory algorithm can greatly improve the system performance with the advantages of reducing task completion time and achieving smooth trajectories.
文摘The construction of Grain Production Functional Zone and Modern Agicultural Zone (Two Zones for short) plays a key role in the development of modern agriculture and solving the quantity and quality problems of agricultural products. The Two Zones serves as the important form and carrier of agricultural standardization and the agricultural standardization provides means and ways for it. The paper puts forward the suggestions and solutions for agricultural standardization in Two Zones in the aspects of boosting standards innovation projects, management and so forth.
基金Supported by LIU Hui Centre for Applied Mathematics of Nankai University and Tianjin University
文摘The generalized complementarity problem includes the well-known nonlinear complementarity problem and linear complementarity problem as special cases.In this paper, based on a class of smoothing functions, a smoothing Newton-type algorithm is proposed for solving the generalized complementarity problem.Under suitable assumptions, the proposed algorithm is well-defined and global convergent.
基金Project(2010ZC13012) supported by the Aviation Science Funds of China
文摘A self-adaptive learning based immune algorithm (SALIA) is proposed to tackle diverse optimization problems, such as complex multi-modal and ill-conditioned prc,blems with the high robustness. The SALIA algorithm adopted a mutation strategy pool which consists of four effective mutation strategies to generate new antibodies. A self-adaptive learning framework is implemented to select the mutation strategies by learning from their previous performances in generating promising solutions. Twenty-six state-of-the-art optimization problems with different characteristics, such as uni-modality, multi-modality, rotation, ill-condition, mis-scale and noise, are used to verify the validity of SALIA. Experimental results show that the novel algorithm SALIA achieves a higher universality and robustness than clonal selection algorithms (CLONALG), and the mean error index of each test function in SALIA decreases by a factor of at least 1.0×10^7 in average.
文摘Recent research has showed increasing interest at the vital role of irrigation ponds that plays at biodiversity conservation,and provides ecological functions at a wide range.However,many irrigation ponds were abolished due to the economic and societal transformation in the rural.In particular,small-scale ponds were abolished and rebuilt to other public uses based on the consensus building process among the community.At the same time,civil organizations also launched initiatives to conserve irrigation ponds for its ecological significance or landscape scenery.However,study pertinent to the small scale ponds in the rural setting is largely neglected.This research aims at revealing the current situation of the utilization and management of small irrigation ponds using a case study of Noto Island in Ishikawa Prefecture.It was found that irrigation ponds are still under the traditional co-management of rural community.The most important finding in this study is that the traditional management of pond water use largely contributes to mitigate the harvest loss from natural disasters such as drought in the face of extreme climate.However,irrigation ponds are facing the threat of degradation due to the sharp decrease of farm population and the existing large number of part time farmers.Therefore,the small scale irrigation ponds and pertinent management and water use allotment should be revalued for its functions at a wide range from the biological and ecological functions and human knowledge system to mitigate disaster threats.
基金supported by the National Natural Science Foundation of China (Grant No. 50875213)
文摘This paper proposes a global topology optimization algorithm based on subset simulation for the singular optimum problem subject to stress constraints of trusses. The constraints are handled by a fitness function which reflects their degree of violation. The rational and global topology results are guaranteed by the judgment of the samples’ rationality and the Metropolis-Hasting algorithm. Three examples show that the established method can quickly reduce the searching region to the feasible region and converge to the global optimum precisely enough for the singular optimum problem.
基金the National Natural Science Foundation of China (Grant Nos. 19871016 and 19731001).
文摘In this paper, we propose a new smooth function that possesses a property not satisfied by the existing smooth functions. Based on this smooth function, we discuss the existence and continuity of the smoothing path for solving the P0 function nonlinear complementarity problem (NCP). Using the characteristics of the new smooth function, we investigate the boundedness of the iteration sequence generated by the non-interior continuation methods for solving the P0 function NCP under the assumption that the solution set of the NCP is nonempty and bounded. We show that the assumption that the solution set of the NCP is nonempty and bounded is weaker than those required by a few existing continuation methods for solving the NCP.
文摘This paper presents a novel analysis for the solution of nonlinear age-structured prob- lem which is of extreme importance in biological sciences. The presented model is very useful but quite complicated. Modified variational iteration method (MVIM) coupled with auxiliary parameter is used to cope with the complexity of the model which subse- quently shows better results as compared to some existing results available in literature. Furthermore, an appropriate way is used for the identification of auxiliary parameter by means of residual function. Numerical examples are presented for the analysis of the pro- posed algorithm. Graphical results along with the discussions re-confirm the efficiency of proposed algorithm. The work proposes a new algorithm where He's polynomials and an auxiliary parameter are merged with correction functional. The suggested scheme is implemented on nonlinear age-structured population models. Graphs are plotted for the residual function that reflects the accuracy and convergence of the presented algorithm.
基金supported by the National Key Research and Development Program of China(2020YFA0908200)the National Natural Science Foundation of China(52073060 and 22002061)+1 种基金the Natural Science Foundation of Jiangsu(BK20200551)the Shenzhen Fundamental Research Program(JCYJ20190813152616459 and JCYJ20210324133214038)。
文摘Wound healing has invariably been a fundamental health concern,demanding manpower and materials and causing financial burdens.In this research,inspired by the hemostatic function of platelets,we proposed a novel bionic hydrogel by covalent amidation crosslinking natural platelet and alginate for wound healing.With the natural functional groups,the platelet-derived hydrogel exhibited outstanding biocompatibility and blood compatibility.By changing the addition ratio of platelets to alginates,the mechanical properties of the achieved hydrogel were variable to cater to different wound environments.Furthermore,silver nanoparticles could be loaded into the void space of the hydrogel which endowed the composites with superior anti-infective properties.We have demonstrated that the bio-inspired platelet hydrogel could promote hemostasis of acute tissue damage,prevent bacterial proliferation,and promote angiogenesis,collagen deposition,and granulation tissue formation in wound healing.These features signify the potential values of the bio-inspired platelet hydrogel in clinical applications.
基金supported by the National Natural Science Foundation of China (Nos.10801102, 0771151)the Sichuan Youth Sciences and Technology Foundation (No.07ZQ026-009) the China Postdoctoral Science Foundation
文摘This paper deals with the standing wave for a Hamiltonian nonlinear wave equation which can be viewed as a representative of the class of equations of interest.On the one hand,by proving a compactness lemma and solving a variational problem,the existence of the standing wave with ground state for the aforementioned equation is proved.On the other hand,the authors derive the instability of the standing wave by applying the potential well argument,the concavity method and an invariant region under the solution flow of the Cauchy problem for the equation under study,and the invariance of the region aforementioned can be shown by introducing an auxiliary functional and a supplementary constrained variational problem.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51177136, 50377035)the Zhuzhou Electric Motor Company of the South China Locomotive & Rolling Stock Corporation,Limited
文摘The inverter-fed motor is a key component of environmental-friendly hybrid cars, high-speed trains, and other industrial applications. After the widespread use of inverter-fed motors, the repetitive impulse surges from inverters were found to cause new insulation problems in inverter-fed motors that were linked to premature insulation failure. The partial discharge (PD) induced by the overvoltage inner stator windings was found to be the root cause of insulation reliability problems. To mitigate this problem, PD detection and life testing at repetitive square voltages should be performed on new types of insulation models and entire motor insulation systems. The obtained partial discharge inception voltage (PDIV) and lifetime of insulation in the tests can be used to evaluate the insulation status of inverter-fed motor insulation systems and thus to improve the insulation designs. At AC voltage conditions, the voltage frequency can significantly affect PD activity. At repetitive square voltage with rapid rise time, the influence of the square voltage frequency on PD activity should be investigated (1) to suggest values for the repetitive square voltage frequency selection for the PDIV and lifetime tests, and (2) to increase the signal-to-noise ratio when extracting PD pulses from strong disturbances generated by the operating switch of impulse generators. Therefore, the main purpose of this paper was to investigate the effects of repetitive square voltage frequency on PD events. Insulation models of both Type I (low-voltage inverter-fed motor) and Type II (high-voltage inverter-fed motor) were used to obtain single-PD and multi-PD statistical features, respectively. Experimental results indicated that higher frequencies caused less PD events with lower PD magnitudes and shorter delay times in one square voltage cycle. This phenomenon was attributed to the different surface charge decay ratios and the initial electron emission probabilities resulting from different square voltage frequencies. Finally, a number of considerations for PD measurements on inverter-fed motors were provided to improve the sensitivity of the PD test system and to obtain high objective insulation lifetime test results, which are used to assess the insulation status of inverter-fed motors.
基金National Natural Science Foundation of China (Grant Nos. 11271294, 11101040, 11431014 and 11371283)Beijing Youth Excellent Talents Program (Grant No. 0264)+1 种基金National Creative Group under Beijing Normal University 985 Projectsthe Fundamental Research Funds for the Central Universities and le Project ANR EVOL
文摘We consider the nearest-neighbor model on the finite tree T with generator L. We obtain a twosided estimate of the spectral gap by factor 2. We also identify explicitly the Lipschitzian norm of the operator(-L)^(-1) in propriate functional space. This leads to the identification of the best constant in the generalized Cheeger isoperimetric inequality on the tree, and to transportation-information inequalities.