Efficient Management of Persistent Knowledge

Although computer speed has steadily increased and memory is getting cheaper, the need for storage managers to deal efficiently with applications that cannot be held into main memory is vital. Dealing with large quantities of clauses implies the use of persistent knowledge and thus, indexing methods are essential to access efficiently the subset of clauses relevant to answering a query. We introduce PerKMan, a storage manager that uses G-trees, and aims at efficient manipulation of large amounts of persistent knowledge. PerKMan may be connected to Prolog systems that offer an external C language interface. As well as the fact that the storage manager allows different arguments of a predicate to share a common index dimension in a novel manner, it indexes rules and facts in the same manner. PerKMan handles compound terms efficiently and its data structures adapt their shape to large dynamic volumes of clauses, no matter what the distribution. The storage manager achieves fast clause retrieval and reasonable use of disk space.     

The Effect of Post-Cooking Holding Times on Sensory Assessment of Low- and High-Fat Beefburgers

ABSTRACT: The effect of post-cooking holding-time on sensory assessment of low (89 g/kg) and high (218 g/kg) fat beefburgers was assessed. Burgers were served to panelists approximately 3 or 18 min after cooking. Fat content influenced fattiness, moistness/juiciness and overall appearance (P < 0.05), overall acceptability and overall texture (P< 0.01) and tenderness and crumbliness (p<0.001). Burgers with the higher fat content had higher scores. Holding-time influenced sensory overall appearance only with lower scores at extended holding times (P < 0.01). Treatment differences were small, mostly less than one sensory scale unit. Higher lightness and yellowness values were found for burgers with higher fat contents.     

农电企业降损节能工作的探讨

阐述了农网降损节能的意义和技术上，管理上的有效措施，指出在线损管理中，只有将理论计算，准确统计，科学分析，营业管理和严打窃电等一系列办法有机地结合起来，才会有良好的效果。     

已二醇二丙烯酸酯对真丝的接枝改性研究

研究了用二醇二丙烯酸酯为接枝单体、过硫酸铵（APS）为引发剂对真丝的接枝共聚反应，分析了接枝率的影响素，并测试了改性真丝的主要应用性能。结果表明：乳液和乙醇/水为溶剂的2种体系都能在真丝上获得较高接枝率。对于乙醇/水体系v(乙醇）：v(H2O）=1:1，接枝单体20～30g/L,2%甲酸4ml，引发剂APS 0.5g/L,65～70℃接枝60min的接枝率高。改性后真丝的断裂强度、延伸度、吸湿性能都可获得改善，对酸、碱的溶解性提高，但染色性能提高不明显，对泛黄性改善一般。     

经济边际在油气资源勘探开发中的应用方法研究

油气资源勘探开发的经济边际分析是从石油企业的边际利润出发，确定石油企业的最优投入产出水平，为作出科学的投资决策和生产决策提供依据，界定了有关油气资源勘探开发经济边际的概念和内涵，探讨了石油企业边际成本和边际收入的确定方法。     

关于混联梯级水电站经济调度的研究

提出采用具有附加线性约束的网络规划法，可把混联梯级水电站分解为几个子网络，简化了每个子网络的求解计算，从而加速大电网复杂的经济调度的计算速度。     

Closed-loop automatic tuning of PID controller for nonlinear systems

In this paper, a robust control system is first proposed which is suitable for the control of a class of nonlinear systems. A parallel connection of a relay to a proportional integral derivative (PID) controller collectively forms the robust controller. The relay ensures robust control by providing a high feedback gain, but it also induces a control chattering phenomenon. Instead of viewing chattering as an undesirable yet inevitable feature, the chattering signals are used as natural excitation signals for identifying an equivalent PID controller using the recursive least squares algorithm. No other explicit input signal is required. Analysis is provided on the stability properties of the control scheme. Simulation results for the level control of fluid in a spherical tank using the scheme are presented.     

填料萃取塔的操作性能及设计计算

系统地介绍了填料抽提塔的两相流动及传质特性，设计计算，对填料塔的设计和操作有一定指导意义。     

炉壁集束碳氧枪在电炉中的应用

介绍了鄂钢电炉厂70t consteel 电炉使用炉壁集束碳氧枪后对经济指标的改善,以及在生产实践中的冶金效果.     

分组网与ISDN互连的性能分析

本文研究分组交换数据网与ＩＳＤＮ互连的性能分析，文中考虑了分组肉与窄带ＩＳＤＮ和宽带ＩＳＤＮ互连时信关所应完成的功能，分别给出了两种情况下的信关排队模型；在信关存储容量分别为有限和无限的情况下，对两种模型进行了求解，给出了阻塞概率和平均延迟的表达式。对于与Ｂ－ＩＳＤＮ互连的情况，提出了用开关确定性过程来描述输出排队的分组到达流，并提出了一种小时隙方法分析ＳＤＰ／Ｄ／１排队。