AIMTo assess the effect of long-term oral nucleos(t)ide analogues (NUCs) therapy on liver volume change in patients with suppress hepatitis B virus (HBV)-related liver cirrhosis.METHODSWe reviewed the data of na&#...AIMTo assess the effect of long-term oral nucleos(t)ide analogues (NUCs) therapy on liver volume change in patients with suppress hepatitis B virus (HBV)-related liver cirrhosis.METHODSWe reviewed the data of naïve patients with HBV-related liver cirrhosis, who had taken oral NUCs therapy, between 2003 and 2007 at Chonbuk University Hospital. We analyzed two consecutive sets of abdominal computerized tomography scans-one at the time of treatment initiation and another at the second-year follow-up. Liver volume was calculated by 3-dimensional liver extraction volumetry program.RESULTSA total of 55 patients (34 males) were included. There was 114.3 mL ± 167.8 mL (12.9% ± 17.9%) of increase in liver volume during the two years of NUCs therapy (993.8 mL ± 242.8 mL at baseline vs 1108.1 mL ± 263.3 mL at two-year follow-up, P < 0.001). The ratio of the measured baseline liver volume to the estimated standard liver volume was improved from 70.8% to 78.0%. An increase in liver volume was shown not only in patients with compensated cirrhosis (P = 0.046) but also in those with decompensated cirrhosis (P < 0.001). Significant factors for volume increases were Child-Turcotte-Pugh grade and model for end-stage liver disease score improvement without virological breakthrough. In multiple linear regression analysis, delta albumin and delta alanine aminotransferase levels showed a significant association with the increase in liver volume (P = 0.002 and 0.005, respectively).CONCLUSIONLong-term oral NUCs therapy in patients with HBV-related liver cirrhosis lead to significant increase in liver volume assessed with 3-dimensional liver extraction volumetry program.展开更多
Some spectral characterizations of positive operators on Hilbert lattices are presented. The application of these results can yield some equivalent relations of an irreducible positive operator. Some related results f...Some spectral characterizations of positive operators on Hilbert lattices are presented. The application of these results can yield some equivalent relations of an irreducible positive operator. Some related results for positive operators on Hilbert lattice are also obtained.展开更多
Quadratic-field cryptosystem is a cryptosystem built from discrete logarithm problem in ideal class groups of quadratic fields(CL-DLP). The problem on digital signature scheme based on ideal class groups of quadratic ...Quadratic-field cryptosystem is a cryptosystem built from discrete logarithm problem in ideal class groups of quadratic fields(CL-DLP). The problem on digital signature scheme based on ideal class groups of quadratic fields remained open, because of the difficulty of computing class numbers of quadratic fields. In this paper, according to our researches on quadratic fields, we construct the first digital signature scheme in ideal class groups of quadratic fields, using q as modulus, which denotes the prime divisors of ideal class numbers of quadratic fields. Security of the new signature scheme is based fully on CL-DLP. This paper also investigates realization of the scheme, and proposes the concrete technique. In addition, the technique introduced in the paper can be utilized to realize signature schemes of other kinds.展开更多
In this paper, fatigue verification of Class 1 nuclear power piping according to ASME Boiler & Pressure Vessel Code, Section III, NB-3600, is addressed. Basic design requirements and relevant verification procedures ...In this paper, fatigue verification of Class 1 nuclear power piping according to ASME Boiler & Pressure Vessel Code, Section III, NB-3600, is addressed. Basic design requirements and relevant verification procedures using Design-By-Analysis are first reviewed in detail. Thereafter, a so-called simplified elastic-plastic discontinuity analysis for further verification when the basic requirements found unsatisfactory is examined and discussed. In addition, necessary computational procedures for evaluating alternating stress intensities and cumulative damage factors are studied in detail. The authors' emphasis is placed on alternative verification procedures, which do not violate the general design principles upon which the code is built, for further verification if unsatisfactory results are found in the simplified elastic-plastic analysis. An alternative which employs a non-linear finite element computation and a refined numerical approach for re-evaluating the cumulative damage factors is suggested. Using this alternative, unavoidable plastic strains can be correctly taken into account in a computationally affordable way, and the reliability of the verification will not be affected by uncertainties introduced in the simplified elastic-plastic analysis through the penalty factor Ke and other simplifications.展开更多
Rising energy costs and growing environmental awareness motivate a critical revision of the design of distillation units. Systematic design techniques, such as the rectification body, column profile map, and temperatu...Rising energy costs and growing environmental awareness motivate a critical revision of the design of distillation units. Systematic design techniques, such as the rectification body, column profile map, and temperature collocation methods, require exact knowledge of all pinch points in a particular system, because these stationary points delineate the possible composition trajectories realizable in separation columns. This paper demonstrates novel methods for rigorously determining all pinch points for the constant relative volatility, ideal and non-ideal systems. Constant relative volatility and ideal solution systems are transformed into one-dimensional polynomial and nonlinear functions, regardless of the number of the components. A deflation method is proposed to locate all zeros in ideal and non-ideal zeotropic problems. For more challenging non-ideal problems, a novel hybrid sequential niche algorithm is used to solve hard azeotropic problems successfully. Finally, the design implications of these pinch point locations are investigated to show how new separation configurations can be devised. Methodically the paper points out the use of rigorous pinch point computations in conjunction with continuous composition profiles for robust distillation design.展开更多
Groebner basis theory for parametric polynomial ideals is explored with the main objec- tive of nfinicking the Groebner basis theory for ideals. Given a parametric polynomial ideal, its basis is a comprehensive GrSbne...Groebner basis theory for parametric polynomial ideals is explored with the main objec- tive of nfinicking the Groebner basis theory for ideals. Given a parametric polynomial ideal, its basis is a comprehensive GrSbner basis if and only if for every specialization of its parameters in a given field, the specialization of the basis is a GrSbnerbasis of the associated specialized polynomial ideal. For various specializations of parameters, structure of specialized ideals becomes qualitatively different even though there are significant relationships as well because of finiteness properties. Key concepts foundational to GrSbner basis theory are reexamined and/or further developed for the parametric case: (i) Definition of a comprehensive Groebner basis, (ii) test for a comprehensive GrSbner basis, (iii) parameterized rewriting, (iv) S-polynomials among parametric polynomials, (v) completion algorithm for directly computing a comprehensive Groebner basis from a given basis of a parametric ideal. Elegant properties of Groebner bases in the classical ideal theory, such as for a fixed admissible term ordering, a unique GrSbner basis can be associated with every polynomial ideal as well as that such a basis can be computed from any Groebner basis of an ideal, turn out to be a major challenge to generalize for parametric ideals; issues related to these investigations are explored. A prototype implementation of the algorithm has been successfully tried on many examples from the literature.展开更多
Rational Univariate Representation (RUR) of zero-dimensional ideals is used to describe the zeros of zero-dimensional ideals and RUR has been studied extensively. In 1999, Roullier proposed an efficient algorithm to...Rational Univariate Representation (RUR) of zero-dimensional ideals is used to describe the zeros of zero-dimensional ideals and RUR has been studied extensively. In 1999, Roullier proposed an efficient algorithm to compute RUR of zero-dimensional ideals. In this paper, we will present a new algorithm to compute Polynomial Univariate Representation (PUR) of zero-dimensional ideals. The new algorithm is based on some interesting properties of Grobner basis. The new algorithm also provides a method for testing separating elements.展开更多
GVW algorithm was given by Gao, Wang, and Volny in computing a Grobuer bases for ideal in a polynomial ring, which is much faster and more simple than F5. In this paper, the authors generalize GVW algorithm and presen...GVW algorithm was given by Gao, Wang, and Volny in computing a Grobuer bases for ideal in a polynomial ring, which is much faster and more simple than F5. In this paper, the authors generalize GVW algorithm and present an algorithm to compute a Grobner bases for ideal when the coefficient ring is a principal ideal domain. K展开更多
We give an algorithm for computing the factor ring of a given ideal in a Dedekind domain with finite rank, which runs in deterministic and polynomial time. We provide two applications of the algorithm:judging whether ...We give an algorithm for computing the factor ring of a given ideal in a Dedekind domain with finite rank, which runs in deterministic and polynomial time. We provide two applications of the algorithm:judging whether a given ideal is prime or prime power. The main algorithm is based on basis representation of finite rings which is computed via Hermite and Smith normal forms.展开更多
Pan and Wang presented a method for computing uniform GrSbner bases for certain ide- als generated by polynomials with parametric exponents in 2006, and two criteria were proposed to determine if a uniform GrSbner bas...Pan and Wang presented a method for computing uniform GrSbner bases for certain ide- als generated by polynomials with parametric exponents in 2006, and two criteria were proposed to determine if a uniform GrSbner basis can be obtained. This paper gives a new algorithmic approach for computing tile uniform GrSbner basis such that Pan and Wang's method could be concluded as a special case. The authors use the method of reduced term order under ring homomorphisnl to get the reduced uniform GrSbner basis. Also the authors point and correct a mistake in Pan and Wang's method. The result is a generalization of approach of Pan and Wang and one could compute the uniform GrSbner basis more efficiently by the new approach.展开更多
文摘AIMTo assess the effect of long-term oral nucleos(t)ide analogues (NUCs) therapy on liver volume change in patients with suppress hepatitis B virus (HBV)-related liver cirrhosis.METHODSWe reviewed the data of naïve patients with HBV-related liver cirrhosis, who had taken oral NUCs therapy, between 2003 and 2007 at Chonbuk University Hospital. We analyzed two consecutive sets of abdominal computerized tomography scans-one at the time of treatment initiation and another at the second-year follow-up. Liver volume was calculated by 3-dimensional liver extraction volumetry program.RESULTSA total of 55 patients (34 males) were included. There was 114.3 mL ± 167.8 mL (12.9% ± 17.9%) of increase in liver volume during the two years of NUCs therapy (993.8 mL ± 242.8 mL at baseline vs 1108.1 mL ± 263.3 mL at two-year follow-up, P < 0.001). The ratio of the measured baseline liver volume to the estimated standard liver volume was improved from 70.8% to 78.0%. An increase in liver volume was shown not only in patients with compensated cirrhosis (P = 0.046) but also in those with decompensated cirrhosis (P < 0.001). Significant factors for volume increases were Child-Turcotte-Pugh grade and model for end-stage liver disease score improvement without virological breakthrough. In multiple linear regression analysis, delta albumin and delta alanine aminotransferase levels showed a significant association with the increase in liver volume (P = 0.002 and 0.005, respectively).CONCLUSIONLong-term oral NUCs therapy in patients with HBV-related liver cirrhosis lead to significant increase in liver volume assessed with 3-dimensional liver extraction volumetry program.
基金Supported by the National Natural Science Foundation of China(19771056,10571113)
文摘Some spectral characterizations of positive operators on Hilbert lattices are presented. The application of these results can yield some equivalent relations of an irreducible positive operator. Some related results for positive operators on Hilbert lattice are also obtained.
文摘Quadratic-field cryptosystem is a cryptosystem built from discrete logarithm problem in ideal class groups of quadratic fields(CL-DLP). The problem on digital signature scheme based on ideal class groups of quadratic fields remained open, because of the difficulty of computing class numbers of quadratic fields. In this paper, according to our researches on quadratic fields, we construct the first digital signature scheme in ideal class groups of quadratic fields, using q as modulus, which denotes the prime divisors of ideal class numbers of quadratic fields. Security of the new signature scheme is based fully on CL-DLP. This paper also investigates realization of the scheme, and proposes the concrete technique. In addition, the technique introduced in the paper can be utilized to realize signature schemes of other kinds.
文摘In this paper, fatigue verification of Class 1 nuclear power piping according to ASME Boiler & Pressure Vessel Code, Section III, NB-3600, is addressed. Basic design requirements and relevant verification procedures using Design-By-Analysis are first reviewed in detail. Thereafter, a so-called simplified elastic-plastic discontinuity analysis for further verification when the basic requirements found unsatisfactory is examined and discussed. In addition, necessary computational procedures for evaluating alternating stress intensities and cumulative damage factors are studied in detail. The authors' emphasis is placed on alternative verification procedures, which do not violate the general design principles upon which the code is built, for further verification if unsatisfactory results are found in the simplified elastic-plastic analysis. An alternative which employs a non-linear finite element computation and a refined numerical approach for re-evaluating the cumulative damage factors is suggested. Using this alternative, unavoidable plastic strains can be correctly taken into account in a computationally affordable way, and the reliability of the verification will not be affected by uncertainties introduced in the simplified elastic-plastic analysis through the penalty factor Ke and other simplifications.
文摘Rising energy costs and growing environmental awareness motivate a critical revision of the design of distillation units. Systematic design techniques, such as the rectification body, column profile map, and temperature collocation methods, require exact knowledge of all pinch points in a particular system, because these stationary points delineate the possible composition trajectories realizable in separation columns. This paper demonstrates novel methods for rigorously determining all pinch points for the constant relative volatility, ideal and non-ideal systems. Constant relative volatility and ideal solution systems are transformed into one-dimensional polynomial and nonlinear functions, regardless of the number of the components. A deflation method is proposed to locate all zeros in ideal and non-ideal zeotropic problems. For more challenging non-ideal problems, a novel hybrid sequential niche algorithm is used to solve hard azeotropic problems successfully. Finally, the design implications of these pinch point locations are investigated to show how new separation configurations can be devised. Methodically the paper points out the use of rigorous pinch point computations in conjunction with continuous composition profiles for robust distillation design.
基金supported by the National Science Foundation under Grant No.DMS-1217054
文摘Groebner basis theory for parametric polynomial ideals is explored with the main objec- tive of nfinicking the Groebner basis theory for ideals. Given a parametric polynomial ideal, its basis is a comprehensive GrSbner basis if and only if for every specialization of its parameters in a given field, the specialization of the basis is a GrSbnerbasis of the associated specialized polynomial ideal. For various specializations of parameters, structure of specialized ideals becomes qualitatively different even though there are significant relationships as well because of finiteness properties. Key concepts foundational to GrSbner basis theory are reexamined and/or further developed for the parametric case: (i) Definition of a comprehensive Groebner basis, (ii) test for a comprehensive GrSbner basis, (iii) parameterized rewriting, (iv) S-polynomials among parametric polynomials, (v) completion algorithm for directly computing a comprehensive Groebner basis from a given basis of a parametric ideal. Elegant properties of Groebner bases in the classical ideal theory, such as for a fixed admissible term ordering, a unique GrSbner basis can be associated with every polynomial ideal as well as that such a basis can be computed from any Groebner basis of an ideal, turn out to be a major challenge to generalize for parametric ideals; issues related to these investigations are explored. A prototype implementation of the algorithm has been successfully tried on many examples from the literature.
基金supported by National Key Basic Research Project of China(Grant No. 2011CB302400)National Natural Science Foundation of China (Grant Nos. 10971217,60821002/F02)
文摘Rational Univariate Representation (RUR) of zero-dimensional ideals is used to describe the zeros of zero-dimensional ideals and RUR has been studied extensively. In 1999, Roullier proposed an efficient algorithm to compute RUR of zero-dimensional ideals. In this paper, we will present a new algorithm to compute Polynomial Univariate Representation (PUR) of zero-dimensional ideals. The new algorithm is based on some interesting properties of Grobner basis. The new algorithm also provides a method for testing separating elements.
基金supported by the National Natural Science Foundation of China under Grant Nos.11071062,11271208Scientific Research Fund of Hunan Province Education Department under Grant Nos.10A033,12C0130
文摘GVW algorithm was given by Gao, Wang, and Volny in computing a Grobuer bases for ideal in a polynomial ring, which is much faster and more simple than F5. In this paper, the authors generalize GVW algorithm and present an algorithm to compute a Grobner bases for ideal when the coefficient ring is a principal ideal domain. K
基金supported by National Natural Science Foundation of China (Grant Nos. 11601202, 11471314 and 11401312)the Natural Science Foundation of the Jiangsu Higher Education Institutions (Grant No. 14KJB110012)+1 种基金the High-Level Talent Scientific Research Foundation of Jinling Institute of Technology (Grant No. jit-b-201527)the National Center for Mathematics and Interdisciplinary Sciences, Chinese Academy of Sciences
文摘We give an algorithm for computing the factor ring of a given ideal in a Dedekind domain with finite rank, which runs in deterministic and polynomial time. We provide two applications of the algorithm:judging whether a given ideal is prime or prime power. The main algorithm is based on basis representation of finite rings which is computed via Hermite and Smith normal forms.
基金supported by the National Natural Science Foundation of China under Grant No.11271040Science and Technology Foundation of Gui Zhou Province LKM[2013]16
文摘Pan and Wang presented a method for computing uniform GrSbner bases for certain ide- als generated by polynomials with parametric exponents in 2006, and two criteria were proposed to determine if a uniform GrSbner basis can be obtained. This paper gives a new algorithmic approach for computing tile uniform GrSbner basis such that Pan and Wang's method could be concluded as a special case. The authors use the method of reduced term order under ring homomorphisnl to get the reduced uniform GrSbner basis. Also the authors point and correct a mistake in Pan and Wang's method. The result is a generalization of approach of Pan and Wang and one could compute the uniform GrSbner basis more efficiently by the new approach.