Testing the parts of mechanical products and ensuring their accuracy to the design requirements are essential to products’ quality, market competitiveness and manufacturers’ maximum economical benefits from these pr...Testing the parts of mechanical products and ensuring their accuracy to the design requirements are essential to products’ quality, market competitiveness and manufacturers’ maximum economical benefits from these products. One of the latest subjects of study in the area of precision measurement is the testing of parts to follow the relative requirements, viz. design requirements for the size tolerance of size features and related geometrical tolerances of the central feature, including the envelope requirement, maximum material requirement and least material requirement. The article analyzes test methods for parts to follow the envelope requirement or maximum material requirement, as well as further requirements of geometrical tolerances for its central feature. The method is effective in improving product quality and rejecting unqualified parts.展开更多
An optimal algorithm for the retrieval of chlorophyll, suspended sediments and gelbstoff of case Ⅱ waters in the Pearl River estuary was established with the optical parameters derived from the in-situ data obtained ...An optimal algorithm for the retrieval of chlorophyll, suspended sediments and gelbstoff of case Ⅱ waters in the Pearl River estuary was established with the optical parameters derived from the in-situ data obtained in Jan. 2003 in the same area. And then, the chlorophyll, suspended sediments and gelbstoff of the SeaWiFS pixels on Jan. 29, 2003 corresponding to the in-situ sites of Jan. 25 and 26, 2003 were synchronously retrieved, with average relative errors of 14.9%, 12.1% and 13.6% for chlorophyll, suspended sediments and gelbstoff, respectively. The research results indicated that the optimal retrieval algorithm established here was relatively fit for the retrieval of the chlorophyll, suspended sediments and gelbstoff of case Ⅱ waters in the Pearl River estuary, and had quite good retrieval accuracy.展开更多
To characterize the gut bacterial microbiota of patients with primary sclerosing cholangitis (PSC) and ulcerative colitis (UC). METHODSStool samples were collected and relevant clinical data obtained from 106 study pa...To characterize the gut bacterial microbiota of patients with primary sclerosing cholangitis (PSC) and ulcerative colitis (UC). METHODSStool samples were collected and relevant clinical data obtained from 106 study participants, 43 PSC patients with (n = 32) or without (n = 11) concomitant inflammatory bowel disease, 32 UC patients, and 31 healthy controls. The V3 and V4 regions of the 16S ribosomal RNA gene were sequenced on Illumina MiSeq platform to cover low taxonomic levels. Data were further processed in QIIME employing MaAsLin and LEfSe tools for analysis of the output data. RESULTSMicrobial profiles in both PSC and UC were characterized by low bacterial diversity and significant change in global microbial composition. Rothia, Enterococcus, Streptococcus, Veillonella, and three other genera were markedly overrepresented in PSC regardless of concomitant inflammatory bowel disease (IBD). Rothia, Veillonella and Streptococcus were tracked to the species level to identify Rothia mucilaginosa, Streptococcus infantus, S. alactolyticus, and S. equi along with Veillonella parvula and V. dispar. PSC was further characterized by decreased abundance of Adlercreutzia equolifaciens and Prevotella copri. Decrease in genus Phascolarctobacterium was linked to presence of colonic inflammation regardless of IBD phenotype. Akkermansia muciniphila, Butyricicoccus pullicaecorum and Clostridium colinum were decreased in UC along with genus Roseburia. Low levels of serum albumin were significantly correlated with enrichment of order Actinomycetales. CONCLUSIONPSC is associated with specific gut microbes independently of concomitant IBD and several bacterial taxa clearly distinguish IBD phenotypes (PSC-IBD and UC).展开更多
This paper investigated the existence of splitting balanced incomplete block designs with blck size 2× k .The necessary conditions for such a design are λ(v-1) ≡0(mod k ),and λv(v- 1)≡0(mod 2 k 2).It will sho...This paper investigated the existence of splitting balanced incomplete block designs with blck size 2× k .The necessary conditions for such a design are λ(v-1) ≡0(mod k ),and λv(v- 1)≡0(mod 2 k 2).It will show that the above necessary conditions are also sufficient for k =3 with the definite exception( v,λ )=(10,1) and with several possible exceptions.展开更多
Primary pancreatic lymphoma(PPL)is an extremely rare form of extranodal malignant lymphoma.The most common histological subtype of PPL is diffuse large B cell lymphoma(DLBCL).In rare cases,PPL can also present as foll...Primary pancreatic lymphoma(PPL)is an extremely rare form of extranodal malignant lymphoma.The most common histological subtype of PPL is diffuse large B cell lymphoma(DLBCL).In rare cases,PPL can also present as follicular lymphoma,small lymphocytic lymphoma,and T cell lymphoma either of non-Hodgkin’s lymphoma or of Hodgkin’s lymphoma.T-cell/histiocyterich large B-cell lymphoma(T/HRBCL)is an uncommon morphologic variant of DLBCL with aggressive clinical course,it is predominantly a nodal disease,but extranodal sites such as bone marrow,liver,and spleen can be involved.Pancreatic involvement of T/HRBCL was not presented before.Herein,we report a 48-year-old male who was hospitalized with complaints of jaundice,dark brown urine,pale stools,and nausea.The radiological evaluation revealed a pancreatic head mass and,following operative biopsy,the tumor was diagnosed as T/HRBCL.The patient achieved remission after six cycles of CHOP chemotherapy.Therefore,T/HRBCL can be treated similarly to the stage-matched DLBCL and both of them get equivalent outcomes after chemotherapy.展开更多
Vertical profiles of chl-a and primary productivity in the middle continental shelf area and eddy area of the East China Sea were studied using data from a cruise in the East China Sea in February to March, 1997 and a...Vertical profiles of chl-a and primary productivity in the middle continental shelf area and eddy area of the East China Sea were studied using data from a cruise in the East China Sea in February to March, 1997 and a cruise in July, 1998. The results showed that chl-a vertical distribution closely related to in situ hydrological and nutrient conditions. Chla-a concentration ranged from 0.22 to 0.35 mg/m 3 and 0.93-1.09 mg/m 3 in the eddy area and in the middle continental shelf area, respectively. In both areas, chl-a concentrations in deep layers were slightly higher than those in shallow layers, but was of the same order of magnitude. In summer, when a thermocline existed in the water column, highest chl-a concentrations appeared at the base of the thermocline layers in both areas. In the eddy area, chl-a concentration maximized at 3l.743 mg/m 3, and averaged l.143 mg/m 3 below 30 m depth. In the middle continental shelf area, the highest chl-a concentration was 2.120 mg/m 3, the average was 1.168 mg/m 3. The primary productivity reached 1418.76 mgC/(m 2·d) in summer and 1360.69 mgC/(m 2·d) in winter. In the eddy area, the primary productivity was 787.50 mgC/(m 2·d) in summer and 159.04 mgC/(m 2·d) in winter. Vertical carbon sinking rate from the deep layer to the bottom in both areas is also discussed in this paper.展开更多
It is difficult to judge whether a given point is a global maximizer of an unconstrained optimization problem. This paper deals with this problem by considering global information via integral and gives a necessary an...It is difficult to judge whether a given point is a global maximizer of an unconstrained optimization problem. This paper deals with this problem by considering global information via integral and gives a necessary and sufficient condition judging whether a given point is a global maximizer of an unconstrained optimization problem. An algorithm is offered under such a condition and finally two test problems are verified via the offered algorithm.展开更多
Passive source localization via a maximum likelihood (ML) estimator can achieve a high accuracy but involves high calculation burdens, especially when based on time-of-arrival and frequency-of-arrival measurements f...Passive source localization via a maximum likelihood (ML) estimator can achieve a high accuracy but involves high calculation burdens, especially when based on time-of-arrival and frequency-of-arrival measurements for its internal nonlinearity and nonconvex nature. In this paper, we use the Pincus theorem and Monte Carlo importance sampling (MCIS) to achieve an approximate global solution to the ML problem in a computationally efficient manner. The main contribution is that we construct a probability density function (PDF) of Gaussian distribution, which is called an important function for efficient sampling, to approximate the ML estimation related to complicated distributions. The improved performance of the proposed method is at- tributed to the optimal selection of the important function and also the guaranteed convergence to a global maximum. This process greatly reduces the amount of calculation, but an initial solution estimation is required resulting from Taylor series expansion. However, the MCIS method is robust to this prior knowledge for point sampling and correction of importance weights. Simulation results show that the proposed method can achieve the Cram6r-Rao lower bound at a moderate Gaussian noise level and outper- forms the existing methods.展开更多
The Wielandt subgroup of a group G, denoted by w(G), is the intersection of the normalizers of all subnormal subgroups of G. In this paper, the authors show that for a p-group of maximal class G, either wi(G) = ζ...The Wielandt subgroup of a group G, denoted by w(G), is the intersection of the normalizers of all subnormal subgroups of G. In this paper, the authors show that for a p-group of maximal class G, either wi(G) = ζi(G) for all integer i or wi(G) = ζi+1(G) for every integer i, and w(G/K) = ζ(G/K) for every normal subgroup g in G with K ≠ 1. Meanwhile, a necessary and sufficient condition for a regular p-group of maximal class satisfying w(G) = ζ2(G) is given. Finally, the authors prove that the power automorphism group PAut(G) is an elementary abelian p-group if G is a non-abelian p- group with elementary ζ(G) ∩ζ1(G).展开更多
Preimplantation genetic diagnosis (PGD) refers to a procedure for genetically analyzing embryos prior to implantation,improving the chance of conception for patients at high risk of transmitting specific inherited dis...Preimplantation genetic diagnosis (PGD) refers to a procedure for genetically analyzing embryos prior to implantation,improving the chance of conception for patients at high risk of transmitting specific inherited disorders.This method has been widely used for a large number of genetic disorders since the first successful application in the early 1990s.Polymerase chain reaction (PCR) and fluorescent in situ hybridization (FISH) are the two main methods in PGD,but there are some inevitable shortcomings limiting the scope of genetic diagnosis.Fortunately,different whole genome amplification (WGA) techniques have been developed to overcome these problems.Sufficient DNA can be amplified and multiple tasks which need abundant DNA can be performed.Moreover,WGA products can be analyzed as a template for multi-loci and multi-gene during the subsequent DNA analysis.In this review,we will focus on the currently available WGA techniques and their applications,as well as the new technical trends from WGA products.展开更多
The purpose of this paper is to derive some pointwise second-order necessary conditions for stochastic optimal controls in the general case that the control variable enters into both the drift and the diffusion terms....The purpose of this paper is to derive some pointwise second-order necessary conditions for stochastic optimal controls in the general case that the control variable enters into both the drift and the diffusion terms.When the control region is convex, a pointwise second-order necessary condition for stochastic singular optimal controls in the classical sense is established; while when the control region is allowed to be nonconvex, we obtain a pointwise second-order necessary condition for stochastic singular optimal controls in the sense of Pontryagin-type maximum principle. It is found that, quite different from the first-order necessary conditions,the correction part of the solution to the second-order adjoint equation appears in the pointwise second-order necessary conditions whenever the diffusion term depends on the control variable, even if the control region is convex.展开更多
In contrast to inorganic solar cells, organic solar cells (OSCs) show advantages such as low cost, light weight, and flexi- bility. In fact, the most attractive feature of OSCs is that they could be produced in larg...In contrast to inorganic solar cells, organic solar cells (OSCs) show advantages such as low cost, light weight, and flexi- bility. In fact, the most attractive feature of OSCs is that they could be produced in large scale and at low cost by roll-to-roll printing, just like printing newspapers, which does not in- volve complicated and high-cost procedures that are required in the production of inorganic solar cells. It is this fascinat- ing feature that has drawn great attention on the OSC study during the past two decades.展开更多
The GARCH diffusion model has received much attention in recent years, as it describes financial time series better when compared to many other models. In this paper, the authors study the empirical performance of Ame...The GARCH diffusion model has received much attention in recent years, as it describes financial time series better when compared to many other models. In this paper, the authors study the empirical performance of American option pricing model when the underlying asset follows the GARCH diffusion. The parameters of the GARCH diffusion model are estimated by the efficient importance sampling-based maximum likelihood (EIS-ML) method. Then the least-squares Monte Carlo (LSMC) method is introduced to price American options. Empirical pricing results on American put options in Hong Kong stock market shows that the GARCH diffusion model outperforms the classical constant volatility (CV) model significantly.展开更多
The stabilization with receding horizon control (RHC) of It5 stochastic time-varying systems is studied in this paper. Based on monotonically non-increasing of optimal cost and stochastic Lyapunov stability theory, ...The stabilization with receding horizon control (RHC) of It5 stochastic time-varying systems is studied in this paper. Based on monotonically non-increasing of optimal cost and stochastic Lyapunov stability theory, a necessary and sufficient stabilization condition on the terminal weighting matrix is proposed, which guarantees the mean-square stability of the closed-loop system. The explicit receding horizon controller is obtained by employing stochastic maximum principle. Simulations demonstrate the effectiveness of the proposed method.展开更多
文摘Testing the parts of mechanical products and ensuring their accuracy to the design requirements are essential to products’ quality, market competitiveness and manufacturers’ maximum economical benefits from these products. One of the latest subjects of study in the area of precision measurement is the testing of parts to follow the relative requirements, viz. design requirements for the size tolerance of size features and related geometrical tolerances of the central feature, including the envelope requirement, maximum material requirement and least material requirement. The article analyzes test methods for parts to follow the envelope requirement or maximum material requirement, as well as further requirements of geometrical tolerances for its central feature. The method is effective in improving product quality and rejecting unqualified parts.
文摘An optimal algorithm for the retrieval of chlorophyll, suspended sediments and gelbstoff of case Ⅱ waters in the Pearl River estuary was established with the optical parameters derived from the in-situ data obtained in Jan. 2003 in the same area. And then, the chlorophyll, suspended sediments and gelbstoff of the SeaWiFS pixels on Jan. 29, 2003 corresponding to the in-situ sites of Jan. 25 and 26, 2003 were synchronously retrieved, with average relative errors of 14.9%, 12.1% and 13.6% for chlorophyll, suspended sediments and gelbstoff, respectively. The research results indicated that the optimal retrieval algorithm established here was relatively fit for the retrieval of the chlorophyll, suspended sediments and gelbstoff of case Ⅱ waters in the Pearl River estuary, and had quite good retrieval accuracy.
基金Supported by Ministry of Health of the Czech Republic,No.15-28064A
文摘To characterize the gut bacterial microbiota of patients with primary sclerosing cholangitis (PSC) and ulcerative colitis (UC). METHODSStool samples were collected and relevant clinical data obtained from 106 study participants, 43 PSC patients with (n = 32) or without (n = 11) concomitant inflammatory bowel disease, 32 UC patients, and 31 healthy controls. The V3 and V4 regions of the 16S ribosomal RNA gene were sequenced on Illumina MiSeq platform to cover low taxonomic levels. Data were further processed in QIIME employing MaAsLin and LEfSe tools for analysis of the output data. RESULTSMicrobial profiles in both PSC and UC were characterized by low bacterial diversity and significant change in global microbial composition. Rothia, Enterococcus, Streptococcus, Veillonella, and three other genera were markedly overrepresented in PSC regardless of concomitant inflammatory bowel disease (IBD). Rothia, Veillonella and Streptococcus were tracked to the species level to identify Rothia mucilaginosa, Streptococcus infantus, S. alactolyticus, and S. equi along with Veillonella parvula and V. dispar. PSC was further characterized by decreased abundance of Adlercreutzia equolifaciens and Prevotella copri. Decrease in genus Phascolarctobacterium was linked to presence of colonic inflammation regardless of IBD phenotype. Akkermansia muciniphila, Butyricicoccus pullicaecorum and Clostridium colinum were decreased in UC along with genus Roseburia. Low levels of serum albumin were significantly correlated with enrichment of order Actinomycetales. CONCLUSIONPSC is associated with specific gut microbes independently of concomitant IBD and several bacterial taxa clearly distinguish IBD phenotypes (PSC-IBD and UC).
基金National Natural Science Foundation ofChina(No.10 4710 93)
文摘This paper investigated the existence of splitting balanced incomplete block designs with blck size 2× k .The necessary conditions for such a design are λ(v-1) ≡0(mod k ),and λv(v- 1)≡0(mod 2 k 2).It will show that the above necessary conditions are also sufficient for k =3 with the definite exception( v,λ )=(10,1) and with several possible exceptions.
文摘Primary pancreatic lymphoma(PPL)is an extremely rare form of extranodal malignant lymphoma.The most common histological subtype of PPL is diffuse large B cell lymphoma(DLBCL).In rare cases,PPL can also present as follicular lymphoma,small lymphocytic lymphoma,and T cell lymphoma either of non-Hodgkin’s lymphoma or of Hodgkin’s lymphoma.T-cell/histiocyterich large B-cell lymphoma(T/HRBCL)is an uncommon morphologic variant of DLBCL with aggressive clinical course,it is predominantly a nodal disease,but extranodal sites such as bone marrow,liver,and spleen can be involved.Pancreatic involvement of T/HRBCL was not presented before.Herein,we report a 48-year-old male who was hospitalized with complaints of jaundice,dark brown urine,pale stools,and nausea.The radiological evaluation revealed a pancreatic head mass and,following operative biopsy,the tumor was diagnosed as T/HRBCL.The patient achieved remission after six cycles of CHOP chemotherapy.Therefore,T/HRBCL can be treated similarly to the stage-matched DLBCL and both of them get equivalent outcomes after chemotherapy.
文摘Vertical profiles of chl-a and primary productivity in the middle continental shelf area and eddy area of the East China Sea were studied using data from a cruise in the East China Sea in February to March, 1997 and a cruise in July, 1998. The results showed that chl-a vertical distribution closely related to in situ hydrological and nutrient conditions. Chla-a concentration ranged from 0.22 to 0.35 mg/m 3 and 0.93-1.09 mg/m 3 in the eddy area and in the middle continental shelf area, respectively. In both areas, chl-a concentrations in deep layers were slightly higher than those in shallow layers, but was of the same order of magnitude. In summer, when a thermocline existed in the water column, highest chl-a concentrations appeared at the base of the thermocline layers in both areas. In the eddy area, chl-a concentration maximized at 3l.743 mg/m 3, and averaged l.143 mg/m 3 below 30 m depth. In the middle continental shelf area, the highest chl-a concentration was 2.120 mg/m 3, the average was 1.168 mg/m 3. The primary productivity reached 1418.76 mgC/(m 2·d) in summer and 1360.69 mgC/(m 2·d) in winter. In the eddy area, the primary productivity was 787.50 mgC/(m 2·d) in summer and 159.04 mgC/(m 2·d) in winter. Vertical carbon sinking rate from the deep layer to the bottom in both areas is also discussed in this paper.
文摘It is difficult to judge whether a given point is a global maximizer of an unconstrained optimization problem. This paper deals with this problem by considering global information via integral and gives a necessary and sufficient condition judging whether a given point is a global maximizer of an unconstrained optimization problem. An algorithm is offered under such a condition and finally two test problems are verified via the offered algorithm.
基金Project supported by the National Natural Science Foundation of China (No. 61201381 ) and the China Postdoctoral Science Foundation (No. 2016M592989)
文摘Passive source localization via a maximum likelihood (ML) estimator can achieve a high accuracy but involves high calculation burdens, especially when based on time-of-arrival and frequency-of-arrival measurements for its internal nonlinearity and nonconvex nature. In this paper, we use the Pincus theorem and Monte Carlo importance sampling (MCIS) to achieve an approximate global solution to the ML problem in a computationally efficient manner. The main contribution is that we construct a probability density function (PDF) of Gaussian distribution, which is called an important function for efficient sampling, to approximate the ML estimation related to complicated distributions. The improved performance of the proposed method is at- tributed to the optimal selection of the important function and also the guaranteed convergence to a global maximum. This process greatly reduces the amount of calculation, but an initial solution estimation is required resulting from Taylor series expansion. However, the MCIS method is robust to this prior knowledge for point sampling and correction of importance weights. Simulation results show that the proposed method can achieve the Cram6r-Rao lower bound at a moderate Gaussian noise level and outper- forms the existing methods.
基金supported by the National Natural Science Foundation of China (No. 11071155)the Key Disciplines of Shanghai Municipality (No. S30104)
文摘The Wielandt subgroup of a group G, denoted by w(G), is the intersection of the normalizers of all subnormal subgroups of G. In this paper, the authors show that for a p-group of maximal class G, either wi(G) = ζi(G) for all integer i or wi(G) = ζi+1(G) for every integer i, and w(G/K) = ζ(G/K) for every normal subgroup g in G with K ≠ 1. Meanwhile, a necessary and sufficient condition for a regular p-group of maximal class satisfying w(G) = ζ2(G) is given. Finally, the authors prove that the power automorphism group PAut(G) is an elementary abelian p-group if G is a non-abelian p- group with elementary ζ(G) ∩ζ1(G).
基金Project supported by the National Basic Research Program (973) of China (No.2007CB948104)the Natural Science Foundation of Zhejiang Province,China (No.Z207021)
文摘Preimplantation genetic diagnosis (PGD) refers to a procedure for genetically analyzing embryos prior to implantation,improving the chance of conception for patients at high risk of transmitting specific inherited disorders.This method has been widely used for a large number of genetic disorders since the first successful application in the early 1990s.Polymerase chain reaction (PCR) and fluorescent in situ hybridization (FISH) are the two main methods in PGD,but there are some inevitable shortcomings limiting the scope of genetic diagnosis.Fortunately,different whole genome amplification (WGA) techniques have been developed to overcome these problems.Sufficient DNA can be amplified and multiple tasks which need abundant DNA can be performed.Moreover,WGA products can be analyzed as a template for multi-loci and multi-gene during the subsequent DNA analysis.In this review,we will focus on the currently available WGA techniques and their applications,as well as the new technical trends from WGA products.
基金supported by the National Basic Research Program of China(973 Program)(Grant No.2011CB808002)National Natural Science Foundation of China(Grant Nos.11221101+4 种基金1123100711401404 and 11471231)the Program for Changjiang Scholars and Innovative Research Team in University(Grant No.IRT1273)the Changjiang Scholars Program from the Chinese Education Ministrythe Spanish Science and Innovation Ministry(Grant No.MTM2011-29306)
文摘The purpose of this paper is to derive some pointwise second-order necessary conditions for stochastic optimal controls in the general case that the control variable enters into both the drift and the diffusion terms.When the control region is convex, a pointwise second-order necessary condition for stochastic singular optimal controls in the classical sense is established; while when the control region is allowed to be nonconvex, we obtain a pointwise second-order necessary condition for stochastic singular optimal controls in the sense of Pontryagin-type maximum principle. It is found that, quite different from the first-order necessary conditions,the correction part of the solution to the second-order adjoint equation appears in the pointwise second-order necessary conditions whenever the diffusion term depends on the control variable, even if the control region is convex.
文摘In contrast to inorganic solar cells, organic solar cells (OSCs) show advantages such as low cost, light weight, and flexi- bility. In fact, the most attractive feature of OSCs is that they could be produced in large scale and at low cost by roll-to-roll printing, just like printing newspapers, which does not in- volve complicated and high-cost procedures that are required in the production of inorganic solar cells. It is this fascinat- ing feature that has drawn great attention on the OSC study during the past two decades.
基金supported by the National Natural Science Foundations of China under Grant No.71201013the National Science Fund for Distinguished Young Scholars of China under Grant No.70825006+1 种基金the Program for Changjiang Scholars and Innovative Research Team in University under Grant No.IRT0916the National Natural Science Innovation Research Group of China under Grant No.71221001
文摘The GARCH diffusion model has received much attention in recent years, as it describes financial time series better when compared to many other models. In this paper, the authors study the empirical performance of American option pricing model when the underlying asset follows the GARCH diffusion. The parameters of the GARCH diffusion model are estimated by the efficient importance sampling-based maximum likelihood (EIS-ML) method. Then the least-squares Monte Carlo (LSMC) method is introduced to price American options. Empirical pricing results on American put options in Hong Kong stock market shows that the GARCH diffusion model outperforms the classical constant volatility (CV) model significantly.
基金supported by the Taishan Scholar Construction Engineering by Shandong Governmentthe National Natural Science Foundation of China under Grant Nos.61120106011 and 61573221
文摘The stabilization with receding horizon control (RHC) of It5 stochastic time-varying systems is studied in this paper. Based on monotonically non-increasing of optimal cost and stochastic Lyapunov stability theory, a necessary and sufficient stabilization condition on the terminal weighting matrix is proposed, which guarantees the mean-square stability of the closed-loop system. The explicit receding horizon controller is obtained by employing stochastic maximum principle. Simulations demonstrate the effectiveness of the proposed method.