In this paper we consider the extreme points of closed convex hull of the class T σ(p,α) and then it is used to determine the coefficient bounds. Some other interesting properties of the class T σ(p,α) are also...In this paper we consider the extreme points of closed convex hull of the class T σ(p,α) and then it is used to determine the coefficient bounds. Some other interesting properties of the class T σ(p,α) are also investigated.展开更多
When the edges of a convex polygon are traversed along one direction,the interior of the convex polygon is always on the same side of the edges. Based on this characteristic of convex polygons,a new algorithm for comp...When the edges of a convex polygon are traversed along one direction,the interior of the convex polygon is always on the same side of the edges. Based on this characteristic of convex polygons,a new algorithm for computing the convex hull of a simple polygon is proposed in this paper,which is then extended to a new algorithm for computing the convex hull of a planar point set. First,the extreme points of the planar point set are found,and the subsets of point candidate for vertex of the convex hull between extreme points are obtained. Then,the ordered convex hull point sequences between extreme points are constructed separately and concatenated by removing redundant extreme points to get the convex hull. The time complexity of the new planar convex hull algorithm is O(nlogh) ,which is equal to the time complexity of the best output-sensitive planar convex hull algorithms. Compared with the algorithm having the same complexity,the new algorithm is much faster.展开更多
New technologies in endoscopic ultrasound(EUS) evaluation have been developed because of the need to improve the EUS and EUS-fine needle aspiration(EUS- FNA) diagnostic rate. This paper reviews the principle, indicati...New technologies in endoscopic ultrasound(EUS) evaluation have been developed because of the need to improve the EUS and EUS-fine needle aspiration(EUS- FNA) diagnostic rate. This paper reviews the principle, indications, main literature results, limitations and future expectations for each of the methods presented. Contrast-enhanced harmonic EUS uses a low mechanical index and highlights slowflow vascularization. This technique is useful for differentiating solid and cystic pancreatic lesions and assessing biliary neoplasms, submucosal neoplasms and lymph nodes. It is also useful for the discrimination of pancreatic masses based on their qualitative patterns; however, the quantitative assessment needs to be improved. The detection of small solid lesions is better, and the EUS-FNA guidance needs further research. The differentiation of cystic lesions of the pancreas and the identification of the associated malignancy features represent the main indications. Elastography is used to assess tissue hardness based on the measurement of elasticity. Despite its low negative predictive value, elastography might rule out the diagnosis of malignancy for pancreatic masses. Needle confocal laser endomicroscopy offers useful information about cystic lesions of the pancreas and is still under evaluation for use with solid pancreatic lesions of lymph nodes.展开更多
In secure multicast, one of the challenging problems is the authentication of multicast packets. This paper presents a novel scheme to address this problem, which combines ideas in both the hash tree schemes and the h...In secure multicast, one of the challenging problems is the authentication of multicast packets. This paper presents a novel scheme to address this problem, which combines ideas in both the hash tree schemes and the hash chain schemes. In this scheme, a group of packets is partitioned into equal-sized subgroups. Then a Merkle hash tree is built for each subgroup of packets, and the hash value of every root is appended to preceding packets to form hash chains. Its performance is analyzed and simulated using Biased Coin Toss loss model and 2-state Markov Chain loss model, respectively. Compared with the original hash chain schemes, results show that this scheme is much more efficient in term of communication overhead.展开更多
Impulsive neutral differential inclusions play an important role in characterizing many social, physical and engineering problems, and the existence of solutions for the initial value problem in Banach spaces has been...Impulsive neutral differential inclusions play an important role in characterizing many social, physical and engineering problems, and the existence of solutions for the initial value problem in Banach spaces has been extensively studied. However, in most cases, the nonlinear term on the right-hand side of differential inclusions has to satisfy the compact or continuous assumptions. The object of this paper is to study the existence of solutions to the initial value problems of the first and second order impulsive neutral functional differential inclusions in Banach spaces under some weaker conditions, where the nonlinear term on the right-hand side does not necessarily satisfy the compact and continuous assumptions. Based on a fixed point theorem for discontinuous multivalued increasing operators, the results are obtained by means of the partial ordering method and measure of noncompactness.展开更多
The objective of this study is to investigate a network failure problem with a significant path, emerging from the context of crisis management, such as in the case of natural disasters. For a given tree with m failed...The objective of this study is to investigate a network failure problem with a significant path, emerging from the context of crisis management, such as in the case of natural disasters. For a given tree with m failed edges, we assume that we have sufficient resources to recover k edges of the m edges. Each node has a positive weight. In this situation, we consider which k edges should be fixed in order to maximize the sum of the weights of the nodes reachable from the significant path. In this paper, we formulate such a problem as a combinatorial problem. Further, we show that a part of our problem may be solved by translating it into the terms of the so-called tree knapsack problem.展开更多
Coalbed methane(CBM) commercial development requires choosing the arrangement of the wells.This should be done by considering the corresponding input-output(investment-profit) efficiencies.Simulations were obtained fr...Coalbed methane(CBM) commercial development requires choosing the arrangement of the wells.This should be done by considering the corresponding input-output(investment-profit) efficiencies.Simulations were obtained from the computer modeling group(CMG) given the reservoir conditions of the Panzhuang block in the southern part of the Qinshui Basin.This is a demonstration region for CBM development located in Shanxi province of northern China.The sensitivity of gas production from a single vertical well to the primary reservoir parameters was estimated first.Then multi-well gas production from three different well patterns was simulated to estimate the most appropriate well spacing.Combining the investment requirements then gave investment-profit efficiencies for these well patterns.A data envelopment analysis(DEA) model was used to optimize the efficiency.The results show that the permeability,the reservoir pressure,and the gas content have an evident impact on single well gas production.The desorption time has little or no affect on production.The equilateral triangular well pattern(ETWP) in a 400 m well spacing is,for multi-well development,the optimal pattern.It has a better input-output ratio,a longer stable yield time,and provides for greater CBM recovery than does either the rectangular well pattern(RWP) or the five point well pattern(FPWP).展开更多
On basis of two definitions that 1. an induced subgraph by a vertex vi E G and its neighbors in G is defined a vertex adjacent closed subgraph denoted by Qi （=G[V（Nvi）]）, with the vertex vi called the hub; 2. A r...On basis of two definitions that 1. an induced subgraph by a vertex vi E G and its neighbors in G is defined a vertex adjacent closed subgraph denoted by Qi （=G[V（Nvi）]）, with the vertex vi called the hub; 2. A r（k,1）-1 vertices connected graph is called a （k,l）-Ramsey graph denoted by RG（k,l）,if and only if 1. RG（k,l） contains only cliques of degree k-1, and its complement contains only cliques of degree l-l; 2. the intersect Qi∩Qj of any two nonadjacent vertices vi and vj of RG（k,1） contains Kk.2, and the intersect Qi∩Qj of any two nonadjacent vertices vi and vj of its complement RG（l,k） contains KI.2. Two theorems that theoreml ： the biggest clique in G is contained in some Qi of G, and theorem2： r（k,l）= [ V（RG（k,I）） I ＋1 are put forward and proved in this paper. With those definitions and theorems as well as analysis of property of chords a method for quick inspection and building RG（k,I） is proposed. Accordingly, RG（10,3） and its complement are built, which are respectively the strongly 29-regular graph and the strongly 10-regular graph on orders 40. We have tested RG（10,3） and its complement RG（3,10）,and gotten r（3,10）=41.展开更多
In this paper,we consider nonconvex-valued functional differential inclusions with nonlinear semigroups in Banach spaces,the existence of the integral solutions is proved.
Plastic bags, though commonly used for packaging of goods, are highly durable and non- biodegradable. Plastic bag litter serves as a negative environmental externality detrimental to animal health and natural beauty o...Plastic bags, though commonly used for packaging of goods, are highly durable and non- biodegradable. Plastic bag litter serves as a negative environmental externality detrimental to animal health and natural beauty of the environment. In an effort to curtail the excessive use of plastic bags in Botswana, the government introduced a plastic levy targeted at consumers at retail points. This study uses primary data collected from 367 respondents randomly selected from six geospatially and purposively selected shopping malls to determine the consumers＇ willingness to pay （WTP） for continued plastic bag usage and their willingness to accept （WTA） to shift to eco-friendly alternatives. The results of the study revealed that open dumping and burning of plastic litter are more common in Maun than in Gaborone, It also showed that there is a significant relationship between the level of education and W＇FP. Further, there is a significant variation in income and education in respect to environmental awareness. The government should improve its efforts of sensitizing the public about the improper disposal of plastic bags.展开更多
文摘In this paper we consider the extreme points of closed convex hull of the class T σ(p,α) and then it is used to determine the coefficient bounds. Some other interesting properties of the class T σ(p,α) are also investigated.
基金Project (No. 2004AA420100) supported by the National Hi-TechResearch and Development Program (863) of China
文摘When the edges of a convex polygon are traversed along one direction,the interior of the convex polygon is always on the same side of the edges. Based on this characteristic of convex polygons,a new algorithm for computing the convex hull of a simple polygon is proposed in this paper,which is then extended to a new algorithm for computing the convex hull of a planar point set. First,the extreme points of the planar point set are found,and the subsets of point candidate for vertex of the convex hull between extreme points are obtained. Then,the ordered convex hull point sequences between extreme points are constructed separately and concatenated by removing redundant extreme points to get the convex hull. The time complexity of the new planar convex hull algorithm is O(nlogh) ,which is equal to the time complexity of the best output-sensitive planar convex hull algorithms. Compared with the algorithm having the same complexity,the new algorithm is much faster.
基金National Grant of the Romanian Education Ministry,No.PN-II-PT-PCCA.2O13-4-11O5/2014
文摘New technologies in endoscopic ultrasound(EUS) evaluation have been developed because of the need to improve the EUS and EUS-fine needle aspiration(EUS- FNA) diagnostic rate. This paper reviews the principle, indications, main literature results, limitations and future expectations for each of the methods presented. Contrast-enhanced harmonic EUS uses a low mechanical index and highlights slowflow vascularization. This technique is useful for differentiating solid and cystic pancreatic lesions and assessing biliary neoplasms, submucosal neoplasms and lymph nodes. It is also useful for the discrimination of pancreatic masses based on their qualitative patterns; however, the quantitative assessment needs to be improved. The detection of small solid lesions is better, and the EUS-FNA guidance needs further research. The differentiation of cystic lesions of the pancreas and the identification of the associated malignancy features represent the main indications. Elastography is used to assess tissue hardness based on the measurement of elasticity. Despite its low negative predictive value, elastography might rule out the diagnosis of malignancy for pancreatic masses. Needle confocal laser endomicroscopy offers useful information about cystic lesions of the pancreas and is still under evaluation for use with solid pancreatic lesions of lymph nodes.
基金Supported by the Natural Science Foundation of China (No. 60173066)
文摘In secure multicast, one of the challenging problems is the authentication of multicast packets. This paper presents a novel scheme to address this problem, which combines ideas in both the hash tree schemes and the hash chain schemes. In this scheme, a group of packets is partitioned into equal-sized subgroups. Then a Merkle hash tree is built for each subgroup of packets, and the hash value of every root is appended to preceding packets to form hash chains. Its performance is analyzed and simulated using Biased Coin Toss loss model and 2-state Markov Chain loss model, respectively. Compared with the original hash chain schemes, results show that this scheme is much more efficient in term of communication overhead.
基金Supported by National Natural Science Foundation of China (No. 10401006)Hebei Province (No. 07M002)
文摘Impulsive neutral differential inclusions play an important role in characterizing many social, physical and engineering problems, and the existence of solutions for the initial value problem in Banach spaces has been extensively studied. However, in most cases, the nonlinear term on the right-hand side of differential inclusions has to satisfy the compact or continuous assumptions. The object of this paper is to study the existence of solutions to the initial value problems of the first and second order impulsive neutral functional differential inclusions in Banach spaces under some weaker conditions, where the nonlinear term on the right-hand side does not necessarily satisfy the compact and continuous assumptions. Based on a fixed point theorem for discontinuous multivalued increasing operators, the results are obtained by means of the partial ordering method and measure of noncompactness.
文摘The objective of this study is to investigate a network failure problem with a significant path, emerging from the context of crisis management, such as in the case of natural disasters. For a given tree with m failed edges, we assume that we have sufficient resources to recover k edges of the m edges. Each node has a positive weight. In this situation, we consider which k edges should be fixed in order to maximize the sum of the weights of the nodes reachable from the significant path. In this paper, we formulate such a problem as a combinatorial problem. Further, we show that a part of our problem may be solved by translating it into the terms of the so-called tree knapsack problem.
基金supported by the National Natural Science Foundation of China (No. 40972207)the National Science and Technology Major Projects (No. 2011ZX05034-005)the PAPD of Jiangsu Higher Education Institutions
文摘Coalbed methane(CBM) commercial development requires choosing the arrangement of the wells.This should be done by considering the corresponding input-output(investment-profit) efficiencies.Simulations were obtained from the computer modeling group(CMG) given the reservoir conditions of the Panzhuang block in the southern part of the Qinshui Basin.This is a demonstration region for CBM development located in Shanxi province of northern China.The sensitivity of gas production from a single vertical well to the primary reservoir parameters was estimated first.Then multi-well gas production from three different well patterns was simulated to estimate the most appropriate well spacing.Combining the investment requirements then gave investment-profit efficiencies for these well patterns.A data envelopment analysis(DEA) model was used to optimize the efficiency.The results show that the permeability,the reservoir pressure,and the gas content have an evident impact on single well gas production.The desorption time has little or no affect on production.The equilateral triangular well pattern(ETWP) in a 400 m well spacing is,for multi-well development,the optimal pattern.It has a better input-output ratio,a longer stable yield time,and provides for greater CBM recovery than does either the rectangular well pattern(RWP) or the five point well pattern(FPWP).
文摘On basis of two definitions that 1. an induced subgraph by a vertex vi E G and its neighbors in G is defined a vertex adjacent closed subgraph denoted by Qi （=G[V（Nvi）]）, with the vertex vi called the hub; 2. A r（k,1）-1 vertices connected graph is called a （k,l）-Ramsey graph denoted by RG（k,l）,if and only if 1. RG（k,l） contains only cliques of degree k-1, and its complement contains only cliques of degree l-l; 2. the intersect Qi∩Qj of any two nonadjacent vertices vi and vj of RG（k,1） contains Kk.2, and the intersect Qi∩Qj of any two nonadjacent vertices vi and vj of its complement RG（l,k） contains KI.2. Two theorems that theoreml ： the biggest clique in G is contained in some Qi of G, and theorem2： r（k,l）= [ V（RG（k,I）） I ＋1 are put forward and proved in this paper. With those definitions and theorems as well as analysis of property of chords a method for quick inspection and building RG（k,I） is proposed. Accordingly, RG（10,3） and its complement are built, which are respectively the strongly 29-regular graph and the strongly 10-regular graph on orders 40. We have tested RG（10,3） and its complement RG（3,10）,and gotten r（3,10）=41.
文摘In this paper,we consider nonconvex-valued functional differential inclusions with nonlinear semigroups in Banach spaces,the existence of the integral solutions is proved.
文摘Plastic bags, though commonly used for packaging of goods, are highly durable and non- biodegradable. Plastic bag litter serves as a negative environmental externality detrimental to animal health and natural beauty of the environment. In an effort to curtail the excessive use of plastic bags in Botswana, the government introduced a plastic levy targeted at consumers at retail points. This study uses primary data collected from 367 respondents randomly selected from six geospatially and purposively selected shopping malls to determine the consumers＇ willingness to pay （WTP） for continued plastic bag usage and their willingness to accept （WTA） to shift to eco-friendly alternatives. The results of the study revealed that open dumping and burning of plastic litter are more common in Maun than in Gaborone, It also showed that there is a significant relationship between the level of education and W＇FP. Further, there is a significant variation in income and education in respect to environmental awareness. The government should improve its efforts of sensitizing the public about the improper disposal of plastic bags.
