基于SVM方法分析蛋白酶体裂解位点的特异性

真核细胞中的泛素-蛋白酶体系统在抗原肽加工呈递途径中发挥着重要作用. 为了进一步研究蛋白酶体的酶切位点特异性, 采用支持向量机(support vector machine, SVM)方法建立了蛋白酶体的酶切位点预测模型. 在相同检验集下, 将本模型性能指标与其他预测模型方法比较, 结果是本模型性能指标优先, 预测准确度为83.1%. 由样本数据相应氨基酸对酶切位点形成的权重系数, 得出蛋白酶体酶切位点及其两侧区域氨基酸的裂解特异性, 反映了蛋白酶体裂解抗原蛋白的相互作用信息, 这表明蛋白酶体对抗原蛋白的酶切处理不是随机的, 而是有一定模式和选择性的.     

Temperature-programmed desoprtion of H2 from the surfaces of pd/support and Pd-Ag/support catalysts (support = Al2O3, SiO2)

Thermal desorption of H₂ from the surface of Pd/support and Pd-Ag/support (support = Al₂O₃, SiO₂) catalysts has been investigated. Two wide desorption peaks can be observed for the 5% Pd/support catalyst. The presence of these peaks in the thermogram indicates that several adsorption states exist, which is the result of occurrance of different adsorption centers of specific bond strengths for hydrogen. The addition of silver to the palladium catalysts causes a considerable decrease in the size of the high temperature desorption peak. It is also worth noting that the temperature of the maximum of the desorption rate remains practically constant for all bimetallic catalysts studied. This means that the activation energy of the hydrogen desorption process does not change after the introduction of silver to the palladium catalyst.     

Set-Valued Kurzweil–Henstock–Pettis Integral

It is shown that the obvious generalization of the Pettis integral of a multifunction obtained by replacing the Lebesgue integrability of the support functions by the Kurzweil–Henstock integrability, produces an integral which can be described – in case of multifunctions with (weakly) compact convex values – in terms of the Pettis set-valued integral.Mathematics Subject Classifications (2000) Primary: 28B20; secondary: 26A39, 28B05, 46G10, 54C60.     

Structure in the Enron Email Dataset

We investigate the structures present in the Enron email dataset using singular value decomposition and semidiscrete decomposition. Using word frequency profiles, we show that messages fall into two distinct groups, whose extrema are characterized by short messages and rare words versus long messages and common words. It is surprising that length of message and word use pattern should be related in this way. We also investigate relationships among individuals based on their patterns of word use in email. We show that word use is correlated to function within the organization, as expected. Lastly, we show that relative changes to individuals' word usage over time can be used to identify key players in major company events. Presented at theWorkshop on Link Analysis, Counterterrorism and Security at the SIAM International Conference on Data Mining, 2005. P.S. Keila is a graduate student in the School of Computing at Queen's University. His research area is data mining in text. D.B. Skillicorn is a professor in the School of Computing at Queen's University, where he heads the Smart Information Management Laboratory. His research area is data mining using matrix decompositions, particularly applied to complex datasets in areas such as biomedicine, geochemistry, counterterrorism and fraud.     

A two-time-scale model for hospital patient flow

^** Email: m.ramakrishnan{at}ms.unimelb.edu.au^*** Email: david.sier{at}csiro.au^**** Email: p.taylor{at}ms.unimelb.edu.au Hospitals are currently facing high incidences of ambulancebypass, long waiting lists for elective procedures and a significantproportion of patients experiencing long stays in the emergencydepartment before moving to a bed in a ward. We observe thatthe system of wards and the emergency department in essenceoperates on two time-scales: the wards operate on a time-scaleof days, whereas the state of the emergency department evolveson a much faster time-scale. This observation has motivatedus to construct a two-time-scale model for a hospital system.The faster time-scale is modelled by a continuous time Markovchain, whereas the slower time-scale (ward occupancy) is modelledby a discrete time Markov chain. Given the nature of the system,the state of the wards has a direct impact on the emergencydepartment.     

商品住宅购买决策涉入对购买意愿的影响：顾客参与和顾客感知价值的链式中介作用

营销是房地产开发全过程中一个重要的环节,为更好地实现销售目标,需要尽可能提升购房者的购买意愿。为探究商品住宅购买意愿的影响机制,构建了以购买决策涉入为自变量、购买意愿为因变量、顾客参与和顾客感知价值为中介变量的结构方程模型。采用方便抽样方法进行问卷调查,使用SPSS 19.0和AMOS 23.0对437个有效样本进行数据分析。实证结果表明,购买决策涉入、顾客参与、顾客感知价值均对购买意愿有显著正向影响;顾客参与、顾客感知价值在购买决策涉入对购买意愿的影响中起到链式中介作用。研究可为房地产企业制定营销策略和改善营销行为提供理论指导。     

Mehler-Fock transforms of generalized functions via the method of adjoints

In this paper we analyse the Mehler-Fock transform of generalized functions via the method of adjoints. For a distribution of compact support, we prove that its Mehler-Fock transform agrees with its transform via the kernel method. A Paley-Wiener type theorem is established.

     

Convex integral functionals

We study nonlinear integral functionals determined by normal convex integrands. First we obtain expressions for their convex conjugate, their -subdifferential and their -directional derivative. Then we derive a necessary and sufficient condition for the existence of an approximate solution for the continuous infimal convolution. We also obtain general conditions which guarantee the interchangeability of the conditional expectation and subdifferential operators. Finally we examine the conditional expectation of random sets.