EON: a component-based approach to automation of protocol-directed therapy

Provision of automated support for planning protocol-directed therapy requires a computer program to take as input clinical data stored in an electronic patient-record system and to generate as output recommendations for therapeutic interventions and laboratory testing that are defined by applicable protocols. This paper presents a synthesis of research carried out at Stanford University to model the therapy-planning task and to demonstrate a component-based architecture for building protocol-based decision-support systems. We have constructed general-purpose software components that (1) interpret abstract protocol specifications to construct appropriate patient-specific treatment plans; (2) infer from time-stamped patient data higher-level, interval-based, abstract concepts; (3) perform time-oriented queries on a time-oriented patient database; and (4) allow acquisition and maintenance of protocol knowledge in a manner that facilitates efficient processing both by humans and by computers. We have implemented these components in a computer system known as EON. Each of the components has been developed, evaluated, and reported independently. We have evaluated the integration of the components as a composite architecture by implementing T-HELPER, a computer-based patient-record system that uses EON to offer advice regarding the management of patients who are following clinical trial protocols for AIDS or HIV infection. A test of the reuse of the software components in a different clinical domain demonstrated rapid development of a prototype application to support protocol-based care of patients who have breast cancer.     

Stability of Mixtoxantrone Hydrochloride in Solution

A stability-indicating reversed-phase high performance liquid chromatographic method was developed for the detection of mitoxantrone HC1 and its degradation products under accelerated degradation conditions. The degradation kinetics of mitoxantrone HC1 in aqueous solution over a pH range of 1.18 to 7.20 and its stability in propylene glycol-or polyethylene glycol 400-based solutions were investigated. The observed rate constants were shown to follow apparent first-order kinetics in all cases. The pH-rate profile shows that maximum stability of mitoxantrone HC1 was obtained at pH 4.01. No general acid or base catalysis from acetate or phosphate buffer species was observed. The catalysis rate constants on the protonated mitoxantrone imposed by hydrogen ion water and hydroxy ion were determined to be 3.72 × 10 min^-1 5.64 × 10-min^-1 and 1.108 × 10^-2min^-1, respectively. The degradation rate constants of mitoxantrone affected by different ionic strength systems. Irradiation with 254 nm UV light at 25±0.5°C was found when canpared with the light-protected controls. Incorporation of nonaqueous propylene glycol or polyethylene glycol in the pH 4.01 mitoxantrone solution shows an increase in its stability at 502±0.5°C.     

三元复合驱波及系数和驱油效率的实验研究

为了搞清三元复合体系提高采收率的机理,通过室内三维物理模拟驱油实验研究了非均质砂岩油田三元复合驱油过程中波及系数与驱油效率的变化特征,量化三元复合驱不同类型储层驱油效率和波及系数对提高采收率的贡献程度.结果表明,在有隔层的条件下,中渗透层贡献程度达到了25.29%,其次是低渗透层,贡献率为44.31%,而高渗透层仅为30.40%;分析认为,三元复合驱的主要作用在于提高驱油效率,而且主要是提高高渗透层的驱油效率,同时能够提高中低渗透层的波及系数.初步得出驱油效率对提高采收率值的贡献率为33.27%,波及系数的贡献率为66.73%.     

PC机远程通信方法研究

在分析用电话线及ＭＯＤＥＭ进行ＰＣ机点－点远程通信和利用局城网ＬＡＮ进行ＰＣ机通信的优缺点后，本文介绍用通信服务器进行ＰＣ机远程通信的方法．     

环形孔径对部分相干光光谱的影响

本文推导了部分相干光在经过环形孔径之后,远场轴上点的光谱S(ω)与环形孔径处光的光谱S~(0)(ω)之间的关系。数值计算结果表明,S(ω)不仅依赖于S~(0)(ω),而且还与环形孔径处光的相干性以及环形孔径的参数有关。     

基于Kullback-Leibler与PCA的概率密度比值估计

为了更好地解决在机器学习和数据挖掘等领域中经常遇到的两个概率密度函数的比值估计问题,文中提出了一种新的概率密度比值估计算法.该算法基于Kullback-Leibler距离,综合混合高斯模型和主成分分析的概率密度比值估计方法,使用混合概率主成分分析为两个概率密度比值函数建模.在概率密度比值估计的过程中,不是分别估计比值函数的分子和分母,而是对整个比值函数进行混合组成建模.算法避免了分别对分子分母的概率密度估计,降低了估计的误差.实验表明该算法能够获得较好的估计结果.     

信息系统安全等级化防护研究探讨

文章针对广州强力安全部门网络安全系统防护提出的一种网络安全系统设计构架;对其中的网络安全体系结构设计与实现进行了详细的分析;提出了安全体系结构模型和管理执行策略模型,并详述了其设计过程。把安全体系结构、安全策略管理的实现和网络安全的实现机制有机地结合在一起。     

支持公平服务的CICQ分层混合调度策略

为到达业务提供性能保障是衡量一个交换系统性能的重要参考.针对现有联合输入交叉点排队交换结构(CICQ)调度策略缺乏基于流的服务质量保障,探讨了在CICQ交换结构实施基于"流"调度的可能性,提出了一种能够为到达业务流的提供公平服务的分层混合调度策略(HSFS).HSFS采用分层的混合调度机制,每个输入、输出端口可独立地进行变长分组交换,其复杂度为O(1),具有良好可扩展特性.理论分析结果表明,HSFS无需加速便能为到达业务提供时延上限、速率和公平性保障.最后,基于SPES对HSFS的性能进行了评估.     

Achieving fair service with a hybrid scheduling scheme for CICQ switches

Providing performance guarantees for arriving traffic flows has become an important measure for today’s routing and switching systems. However, none of current scheduling algorithms built on CICQ (combined input and cross-point buffered) switches can provide flow level performance guarantees. Aiming at meeting this requirement, the feasibility of implementing flow level scheduling is discussed thoroughly. Then, based on the discussion, it comes up with a hybrid and stratified fair scheduling (HSFS) scheme, which is hierarchical and hybrid, for CICQ switches. With HSFS, each input port and output port can schedule variable length packets independently with a complexity of O(1). Theoretical analysis show that HSFS can provide delay bound, service rate and fair performance guarantees without speedup. Finally, we implement HSFS in SPES (switch performance evaluation system) to verify the analytical results.