Graph realization from a matrix is an important topic in network topology. This paper presents an algorithm for the realization of a linear tree based on the study of the properties of the number of the single-link lo...Graph realization from a matrix is an important topic in network topology. This paper presents an algorithm for the realization of a linear tree based on the study of the properties of the number of the single-link loops that are incident to each tree branch in the fundamental loop matrix Bf. The proposed method judges the pendent properties of the tree branches, determines their order one by one and then achieves the realization of the linear tree. The graph that corresponds to Bf is eventually constructed by adding links to the obtained linear tree. The proposed method can be extended for the realization of a general tree.展开更多
Suffix trees are the key data structure for text string matching, and are used in wide application areas such as bioinformatics and data compression. Ukkonen algorithm is deeply investigated and a new algorithm, which...Suffix trees are the key data structure for text string matching, and are used in wide application areas such as bioinformatics and data compression. Ukkonen algorithm is deeply investigated and a new algorithm, which decreases the number of memory operations in construction and keeps the result tree sequential, is proposed. The experiment result shows that both the construction and the matching procedure are more efficient than Ukkonen algorithm.展开更多
This paper describes a simple method of generating concentration gradients with linear and parabolic profiles by using a Christmas tree-shaped microfluidic network.The microfluidic gradient generator consists of two p...This paper describes a simple method of generating concentration gradients with linear and parabolic profiles by using a Christmas tree-shaped microfluidic network.The microfluidic gradient generator consists of two parts：a Christmas tree-shaped network for gradient generation and a broad microchannel for detection.A two-dimensional model was built to analyze the flow field and the mass transfer in the microfluidic network.The simulating results show that a series of linear and parabolic gradient profiles were generated via adjusting relative flow rate ratios of the two source solutions（R_L^2≥0.995 and _PR^2≥0.999）,which could match well with the experimental results（R_L^2≥0.987 and _PR^2≥0.996）.The proposed method is promising for the generation of linear and parabolic concentration gradient profiles,with the potential in chemical and biological applications such as combinatorial chemistry synthesis,stem cell differentiation or cytotoxicity assays.展开更多
This paper presents a new dimension reduction strategy for medium and large-scale linear programming problems. The proposed method uses a subset of the original constraints and combines two algorithms: the weighted av...This paper presents a new dimension reduction strategy for medium and large-scale linear programming problems. The proposed method uses a subset of the original constraints and combines two algorithms: the weighted average and the cosine simplex algorithm. The first approach identifies binding constraints by using the weighted average of each constraint, whereas the second algorithm is based on the cosine similarity between the vector of the objective function and the constraints. These two approaches are complementary, and when used together, they locate the essential subset of initial constraints required for solving medium and large-scale linear programming problems. After reducing the dimension of the linear programming problem using the subset of the essential constraints, the solution method can be chosen from any suitable method for linear programming. The proposed approach was applied to a set of well-known benchmarks as well as more than 2000 random medium and large-scale linear programming problems. The results are promising, indicating that the new approach contributes to the reduction of both the size of the problems and the total number of iterations required. A tree-based classification model also confirmed the need for combining the two approaches. A detailed numerical example, the general numerical results, and the statistical analysis for the decision tree procedure are presented.展开更多
目的分析鼻咽癌患者日均住院费用主要影响因素并提出合理控费建议。方法采集广西某三级甲等公立医院2019年—2023年鼻咽癌出院患者病案首页信息7038条,使用线性回归、决策树和随机森林3种机器学习模型分析鼻咽癌日均住院费用影响因素。...目的分析鼻咽癌患者日均住院费用主要影响因素并提出合理控费建议。方法采集广西某三级甲等公立医院2019年—2023年鼻咽癌出院患者病案首页信息7038条,使用线性回归、决策树和随机森林3种机器学习模型分析鼻咽癌日均住院费用影响因素。结果从决定系数(Coefficient of Determination,RSQ)、均方根误差(Root Mean Squared Error,RMSE)、平均绝对误差(Mean Absolute Error,MAE)3个评价指标的计算结果来看,随机森林模型的性能最好,其在训练集与测试集上的RSQ分别为0.952、0.658,RMSE分别为170.000、391.000,MAE分别为99.900、238.000,且影响鼻咽癌日均住院费用的主要因素为实际住院天数、自付金额、手术用一次性医用材料费、影像学诊断费、实验室诊断费。结论随机森林模型能够较好地识别鼻咽癌日均住院费用的主要影响因素。建议重点关注自费项目、影像学及实验室检查项目、医用耗材等费用的合理性,减少不必要的检查和治疗,按标准合理使用一次性医用耗材,逐步减轻患者住院费用负担。展开更多
The main goal of this paper is to study the following combinatorial problem : given a finite set E = (e1, e2, ...,em} and a subset family a - [S1,S2, ... ,Sk} of E , does there exist a tree T with the edge set E such ...The main goal of this paper is to study the following combinatorial problem : given a finite set E = (e1, e2, ...,em} and a subset family a - [S1,S2, ... ,Sk} of E , does there exist a tree T with the edge set E such that each induced subgraph T[Si] of Si is precisely a path (1≤i≤k) ?展开更多
文摘Graph realization from a matrix is an important topic in network topology. This paper presents an algorithm for the realization of a linear tree based on the study of the properties of the number of the single-link loops that are incident to each tree branch in the fundamental loop matrix Bf. The proposed method judges the pendent properties of the tree branches, determines their order one by one and then achieves the realization of the linear tree. The graph that corresponds to Bf is eventually constructed by adding links to the obtained linear tree. The proposed method can be extended for the realization of a general tree.
基金supported by the National Natural Science Foundation of China(6050203260672068).
文摘Suffix trees are the key data structure for text string matching, and are used in wide application areas such as bioinformatics and data compression. Ukkonen algorithm is deeply investigated and a new algorithm, which decreases the number of memory operations in construction and keeps the result tree sequential, is proposed. The experiment result shows that both the construction and the matching procedure are more efficient than Ukkonen algorithm.
基金Supported by the National Natural Science Foundation of China(81372358,81527801,51303140,and 81602489)the Natural Science Foundation of Hubei Province(2014CFA029)+1 种基金the Colleges of Hubei Province Outstanding Youth Science and Technology Innovation Team(T201305)the Applied Foundational Research Program of Wuhan Municipal Science and Technology Bureau(2015060101010056)
文摘This paper describes a simple method of generating concentration gradients with linear and parabolic profiles by using a Christmas tree-shaped microfluidic network.The microfluidic gradient generator consists of two parts：a Christmas tree-shaped network for gradient generation and a broad microchannel for detection.A two-dimensional model was built to analyze the flow field and the mass transfer in the microfluidic network.The simulating results show that a series of linear and parabolic gradient profiles were generated via adjusting relative flow rate ratios of the two source solutions（R_L^2≥0.995 and _PR^2≥0.999）,which could match well with the experimental results（R_L^2≥0.987 and _PR^2≥0.996）.The proposed method is promising for the generation of linear and parabolic concentration gradient profiles,with the potential in chemical and biological applications such as combinatorial chemistry synthesis,stem cell differentiation or cytotoxicity assays.
文摘This paper presents a new dimension reduction strategy for medium and large-scale linear programming problems. The proposed method uses a subset of the original constraints and combines two algorithms: the weighted average and the cosine simplex algorithm. The first approach identifies binding constraints by using the weighted average of each constraint, whereas the second algorithm is based on the cosine similarity between the vector of the objective function and the constraints. These two approaches are complementary, and when used together, they locate the essential subset of initial constraints required for solving medium and large-scale linear programming problems. After reducing the dimension of the linear programming problem using the subset of the essential constraints, the solution method can be chosen from any suitable method for linear programming. The proposed approach was applied to a set of well-known benchmarks as well as more than 2000 random medium and large-scale linear programming problems. The results are promising, indicating that the new approach contributes to the reduction of both the size of the problems and the total number of iterations required. A tree-based classification model also confirmed the need for combining the two approaches. A detailed numerical example, the general numerical results, and the statistical analysis for the decision tree procedure are presented.
文摘目的分析鼻咽癌患者日均住院费用主要影响因素并提出合理控费建议。方法采集广西某三级甲等公立医院2019年—2023年鼻咽癌出院患者病案首页信息7038条,使用线性回归、决策树和随机森林3种机器学习模型分析鼻咽癌日均住院费用影响因素。结果从决定系数(Coefficient of Determination,RSQ)、均方根误差(Root Mean Squared Error,RMSE)、平均绝对误差(Mean Absolute Error,MAE)3个评价指标的计算结果来看,随机森林模型的性能最好,其在训练集与测试集上的RSQ分别为0.952、0.658,RMSE分别为170.000、391.000,MAE分别为99.900、238.000,且影响鼻咽癌日均住院费用的主要因素为实际住院天数、自付金额、手术用一次性医用材料费、影像学诊断费、实验室诊断费。结论随机森林模型能够较好地识别鼻咽癌日均住院费用的主要影响因素。建议重点关注自费项目、影像学及实验室检查项目、医用耗材等费用的合理性,减少不必要的检查和治疗,按标准合理使用一次性医用耗材,逐步减轻患者住院费用负担。
基金Supported by the National Natural Science Foundation of China
文摘The main goal of this paper is to study the following combinatorial problem : given a finite set E = (e1, e2, ...,em} and a subset family a - [S1,S2, ... ,Sk} of E , does there exist a tree T with the edge set E such that each induced subgraph T[Si] of Si is precisely a path (1≤i≤k) ?
