基于多页的龙芯2F软TLB重载入异常处理改进

龙芯2F系统在TLB替换处理上开销较大,现有软TLB技术从减少TLB重载入异常处理时间方面考虑,利用软TLB来缓存TLB表项,提高替换处理中Cached命中率,减少了重载入异常处理时间。为进一步提高TLB效率,设计采用多页技术提高TLB的覆盖率,减少TLB替换次数,进而减少重载入异常处理的次数,达到提高系统性能的目的。     

基于SOAP的Web服务中的异常处理方法

在构建基于SOAP协议的Web服务过程中,针对Web服务中异常处理存在的问题,提出了一种Web服务中的异常处理新方法:集成代理技术和服务器端加入异常监测.这种方法直接将Web服务的异常消息转换为SOAP消息,通过代理转发到客户端,使用户更好地了解Web服务当前的运行状态,从而提高软件的健壮性.     

基于堆栈回溯的异常处理

针对异常发生时无法及时有效利用异常发生的上下文信息的问题,在堆栈回溯获得上下文信息的基础上,提出一种能够记录异常信息便于线下分析,同时能够基于预设规则库支持线上对系统应用进行重构的异常处理方法。对PowerPC构架下的堆栈结构进行研究并设计基于堆栈回溯的函数溯源算法;对系统工作状态进行分析抽象,采用有限状态机建立系统异常处理时的状态迁移模型,阐述异常处理的设计实现过程。实验结果表明,该方法能够有效实现对异常的线上线下处理,提升了改进系统应用缺陷的效率,增强了系统应用的容错性和健壮性。     

Implementation of blocking coordinated atomic actions based on forward error recovery

The coordinated atomic action concept was proposed as a means for providing fault tolerance in complex objectoriented systems that incorporate both cooperative and competitive concurrency. This paper has two purposes: to discuss a particular implementation of this concept and to address a number of the implementation issues that are common to any experiments with this concept. Our implementation relies on a detailed set of programming conventions for the standard Ada 95 language and uses a scheme of forward error recovery incorporating concurrent exception handling and resolution. Ada 95 has a number of unique features which make it a particularly good choice for our experiments. We believe that our approach is practical and useful for many critical applications with high dependability requirements.     

基于流演算的智能体行动推理模型设计与实现

并发约束程序设计在人工智能程序设计领域中占据越来越重要的位置,约束处理规则作为新一代的并发程序设计正倍受关注.对约束处理规则和流演算理论及其实现语言FLUX进行了研究,结合流演算和JCHR推理模型优点,设计了一种基于Java的流演算解释器JFLUX,同时提出了一个基于目标驱动的,在不完全可知的虚拟环境中通过感知到的有限信息进行自主行动推理能力的智能体模型,实现了办公室场景中智能体行动推理系统.     

An evaluation of classification algorithms for manual material handling tasks based on data obtained using wearable technologies

With recent progress in wearable measurement systems, physical exposures can be feasibly assessed at high precision in the workplace. Such systems, however, generally lack contextual information for a given job (e.g. task type, duration). To extract such information, we explored three classification algorithms to classify manual material handling (MMH) tasks during a simulated job in a laboratory, using several combinations of outputs from commercially available inertial motion capture and in-shoe pressure measurement systems. A total of 10 participants completed three replications of four cycles of a simulated job. Precision and recall values of ≥ ～90% and 80%, respectively, and errors in estimated task duration of < ～14%, could be achieved across the MMH task examined. Classification performance, however, varied between classification algorithms, input data sets and task types. Overall, combining wearable technology with task classification could be an effective approach for field-based exposure assessment, though field-testing is needed to demonstrate the applicability of this method.

Practitioner Summary: Combining wearable technologies with task classification was explored to extract exposure context, specifically task type and duration. Results supported that task classification can facilitate the use of wearable technologies in field-based exposure assessment, specifically by aiding in task identification from within the rather large data sets obtained from these technologies.     

Benefits of user-oriented software development based on an iterative cyclic process model for simultaneous engineering

The current state of traditional software development is surveyed and essential problems are investigated on the basis of empirical data and theoretical considerations. The concept of optimisation cycle is proposed as a solution for simultaneous engineering. The relationships of several different kinds of local optimisation cycles to the specifications, the communications, and the optimisation problem are integrated into a concept of participatory software development. Software development without integrated work- and task-organisational development is sub-optimal. User participation and prototyping significantly decrease cost and time over-runs. Process moderation methods (e.g. workshops) are time effective and lead to best results for the analysis of requirements.

Relevance to industry

There is a growing realisation that the construction, implementation and performance of modern software products crucially depends on getting the social and organisational issues right. The user-oriented approach outlined in the paper explicitly aims to present a process model that incorporates method and techniques for the requirements analysis. The practical problems of this iterative cyclic process model are discussed and recommendations are made to guide industrial managers, engineers and human factor specialists involved in the process of simultaneous production.     

Systematic identifiability study based on the Fisher Information Matrix for reducing the number of parameters calibration of an activated sludge model

This work proposes a procedure for calibration and validation of complex models by systematically obtaining identifiable parameter subsets according to the available data. The procedure uses the new RDE criteria calculated from the Fisher Information Matrix (FIM) as the ratio of normalized D to modified E criteria (RDE). It does not require expert knowledge and it defines automatically the dimension of the identifiable subset without requiring a threshold for the RDE. It was applied successfully to the study of the IWA-ASM2d model, which was implemented, calibrated and validated for an anaerobic/anoxic/oxic (A²/O) pilot WWTP operated under three different influent ammonium concentrations (15, 20 and 30 mg/L) and two internal recycling ratios (IRR = 2 and 5). Starting from 51 among all the ASM2d parameters, a sensitivity analysis around the ASM2d default values was performed. From the sensitivity ranking, the 20 best-ranked parameters were named “seeds”, since each one served for growing a parameter subset for model calibration. The subset generation process added to the seed a parameter that presented the highest RDE among all the remaining parameters of the sensitivity ranking. The process of parameter addition was repeated until the RDE decreased from the current iteration to the previous one. The best subset determined by the methodology {b_PAO, Y_PO4, μ_A} presented the highest possible value of the RDE. Finally, the simulation of the WWTP with this subset fitted adequately the experimental data while the parameters obtained had low confidence intervals.     

基于元数据与角色的煤矿综合信息管理系统权限控制模型设计与实现

分析了现有煤矿信息管理系统中权限控制策略的不足,指出基本的账户控制策略不仅功能简单,且在系统运行过程中无法修改权限,而基于角色的访问控制策略缺少对系统数据的区分,不利于系统的扩展与维护;提出了基于元数据与角色的权限控制模型,通过对用户可访问元数据范围的配置与限制,实现了对用户功能权限和数据权限的管理,并通过元控件实现了权限管理的模块化设计与开发,减少了代码重复率和逻辑复杂度。该模型已应用于多个煤矿综合信息管理系统中,具有很好的灵活性和可操作性。