Reformulating the entropic contribution in molecular docking scoring functions

We have derived, in the context of the Rigid Rotor Harmonic Approximation (RRHO), a general mass and Planck's constant h independent expression for the dissociation free energy in ligand–receptor systems, featuring a systematically (anti‐binding) additive negative entropic term depending on readily available ligand–receptor quantities. The proposed RRHO expression allows to straightforwardly compute the absolute standard dissociation free energy without resorting to expensive normal mode analysis or other dynamical matrix‐based techniques for evaluating the entropic contribution, hence providing an effective scoring function for assessing docking poses with no adjustable parameters. Our RRHO formula was tested on a set of 55 ligand–receptor systems obtaining correlation coefficients and unsigned mean errors comparable to or better than those obtained with computationally demanding techniques for the dissociation entropy assessment. The proposed compact reformulation of the RRHO entropy term could constitute the basis for new and more effective scoring functions in molecular docking‐based high‐throughput virtual screening for drug discovery. © 2016 Wiley Periodicals, Inc.     

一种新的组合模型在信用评分中的应用

针对信用评分的特点,首先对传统的Bagging算法进行改进,然后基于不同的基分类器构建多个改进的Bagging组合模型,最后根据一种全新的方式将其组合,得到双层组合模型.通过实证分析得出以下结论:一、与原Bagging算法相比,改进算法能有效降低第二类错误率;二、与单层组合模型相比,多层组合模型能进一步降低第二类错误率和损失率.     

属性识别预警系统(AFS)——一种新的信用评价方法

在属性集和属性测度函数的基础上建立了属性测度预警系统.利用我国深、沪两交易所2000年公布的106家上市公司作为训练样本,计算出“差”企业和“好”企业的属性测度均值,构造出属性测度函数.进而对2001年公布的13家预亏公司进行预警分析,用置信度准则及最大属性测度准则判别,预警准确率分别达到92.31%和100%.因此,属性识别预警系统在信用评价方面具有良好的应用前景.     

基于矩阵判定分析法和小波网络的银行信贷信用分类方法

分析了矩阵判定分析法和小波网络在解决银行信贷信用分类问题上各自的优缺点,并在此基础上将这两种方法结合起来解决银行信贷信用分类问题．实证分析表明,该模型比单独使用矩阵判定分析法或小波网络的分类准确率要高。     

Prediction and analysis of binding affinities for chemically diverse HIV-1 PR inhibitors by the modified SAFE_p approach

One of the biggest challenges in the "in silico" screening of enzyme ligands is to have a protocol that could predict the ligand binding free energies. In our group we have developed a very simple screening function (referred to as solvent accessibility free energy of binding predictor, SAFE_p) which we have applied previously to the study of peptidic HIV-1 protease (HIV-1 PR) inhibitors and later to cyclic urea type HIV-1 PR inhibitors. In this work, we have extended the SAFE_p protocol to a chemically diverse set of HIV-1 PR inhibitors with binding constants that differ by several orders of magnitude. The resulting function is able to reproduce the ranking and in many cases the value of the inhibitor binding affinities for the HIV-1 PR, with accuracy comparable with that of costlier protocols. We also demonstrate that the binding pocket SAFE_p analysis can contribute to the understanding of the physical forces that participate in ligand binding. The analysis tools afforded by our protocol have allowed us to identify an induced fit phenomena mediated by the inhibitor and have demonstrated that larger fragments do not necessarily contribute the most to the binding free energy, an outcome partially brought about by the substantial role the desolvation penalty plays in the energetics of binding. Finally, we have revisited the effect of the Asp dyad protonation state on the predicted binding affinities.     

计算机应用能力考试系统的设计与实现

通过计算机应用能力考试系统开发,对全程自动化考试系统的流程和功能进行详细设计,利用网络技术和数据库技术实现系统方案设计,操作题自动阅卷获取操作信息的方法和自动评判的策略得以圆满解决,控制难易程度的随机出题方法得到实际应用。     

Network analysis of protein-protein interaction

Residue networks are constructed by defining the residues as the vertices and atom contacts between them as the edges. The residue network of a protein complex is divided into two types of networks, i.e. the hydrophobic and the hydrophilic residue networks. By analyzing the network parameters, it is found that the correct binding complex conformations are of both higher sum of the interface degree values and lower characteristic path length than those incorrect ones. These features reflect that the correct bind-ing complex conformations have better geometric and/or residue type complementarity, and the correct binding modes are very important for preserving the characteristic path lengths of native protein complexes. In addition, two scoring terms are proposed based on the network parameters, in which the characteristics of the entire complex shape and residue type complementarity are taken into account. These network-based scoring terms have also been used in conjunction with other scoring terms, and the new multi-term scoring HPNCscore is devised in this work. It can improve the discrimination of the combined scoring function of RosettaDock more than 12%. This work might enhance our knowledge of the mechanisms of protein-protein interactions and recognition.     

一种基于脆弱点依赖图的脆弱性评估方法

为弥补目前网络脆弱性评估系统比较简单、评估结果不全面不准确的不足,提出一种基于脆弱点依赖图的网络脆弱性评估方法,并在该评估方法基础上开发出相应的评估系统.该方法吸收了通用弱点评价体系(CVSS)的优势,同时与目标网络的脆弱点依赖图很好地结合起来,可对网络脆弱性做出一个客观评价.在计算过程中,该方法将脆弱性可利用性和脆弱性影响分开计算,并与实际目标网络中的脆弱点依赖图相结合,从而使得计算值更有参考和实用价值.     

ATP男子单打不同场地类型比赛得分方式的对比研究

运用文献资料、录像统计、数理统计等研究方法,对网球运动员在不同场地的比赛得分情况进行对比研究,探讨男子网球运动员在不同场地类型比赛的得失分规律,研究表明:在红土球场比赛中,运动员的主动失误较少,技战术发挥最稳定,但各项技术的运用较为单一;在草地球场比赛中,运动员的进攻意识非常明显,主动得分的效率最高;在硬地球场比赛中,运动员各项技术使用较为均衡,战术运用灵活多变,但失误率最高.     

新颖的面向网络服务的动态信任模型

提出一种新颖的面向网络服务的动态信任模型.引入信任评价与区间直觉模糊数的对应关系,给出基于信任需求属性的经验信任、邻居推荐信任及代理推荐信任的计算、合成、及综合运算.同时,采用精确函数比来确定信任属性的权重因子,而时间序列权重因子则由指数分布的逆形式确定.最终以总体信任的得分函数及心性因素来区分信任服务.仿真实验表明,该模型可有效的建立实体间的信任关系并遏制恶意实体的攻击.