加强企业应收账款风险管理

由于商业信用的发展,企业间赊销赊购现象已非属偶然。而由赊销赊购带来的应收账款风险,一直困扰着企业,使企业不能有再生产所需的充足的资金。应认真总结其形成的原因,采取有效的措施,避免或减少应收账款风险,以加速资金的收回。     

Survival of Staphylococcus aureus ATCC 13565 in Intermediate Moisture Foods is Highly Variable

Staphylococcus aureus is a gram-positive, enterotoxin-producing coccus. It is a hardy organism and known to survive over a wide range of water activities, pH values, and temperatures. The objective of this study was to model the survival or gradual inactivation of S. aureus ATCC 13565 in intermediate moisture foods (IMFs). Various initial concentrations (approximately 10(1), 10(2), 10(3), and 10(4) CFU/g) were used to inoculate three different IMFs (beefsteak, bread, and chicken pockets). Viable counts were determined up to 60 days using tryptic soy agar. Inoculum size did not influence the survival or gradual inactivation of S. aureus in these foods. The rate of change (increase or decrease) in log CFU/day was calculated for every consecutive pair of data points and by linear regression for each inactivation curve. Both consecutive pair and linear regression rates of change were fit to logistic distributions (with parameters alpha and beta) for each food. Based on the distribution parameters, survival or gradual inactivation of S. aureus was predicted by computer simulation. The simulations indicated an overall decline in S. aureus population over time, although a small fraction of samples in the consecutive pair simulation showed a slight population increase even after 60 days, consistent with the observed data. Simulation results were compared to predictions from other computer models. The models of Stewart et al., were fail-safe, predicting the possibility of significant growth only after > 3,000 days. The USDA pathogen modeling program predictions were found to be fail-dangerous, predicting declines at least four times faster than observed.     

论非公有制企业和谐稳定劳资关系的必要性和可能性

我国劳资关系紧张现状不容忽视,解决这一问题的前提是充分认识建立和谐劳资关系的必要性和可能性。文章从社会主义初级阶段的国情、非公有制企业与国家经济发展的需要等方面论证了非公有制企业中建立和谐稳定劳资关系的必要性;从现阶段我国劳资双方统一性为主的现实与中外劳资关系协调的历史两个方面探讨了建立和谐稳定劳资关系的可能性。     

电磁-温度耦合条件下推力磁轴承涡流损耗分析

针对一类以实心推力盘为主要热源的电磁轴承转子系统，研究了电磁-温度耦合条件下从线圈加电到稳定运行整个过程中的电磁场，给出了电磁场涡流损耗的解析计算方法．通过将实例的计算结果与有限元方法及实验结果对比表明，采用该解析计算方法可简单、快捷及准确地解决系统初步设计时的参数选定问题．     

平行带状线间加孔栅的抗耦合干扰技术研究

针对平行带状线间的耦合问题,比较了平行带状线间不加孔栅和加孔栅的耦合干扰问题,研究了平行带状线间距不同时加不同孔栅结构的抗耦合干扰情况,分析了孔径与反射损耗的关系。通过计算与仿真,得到了一种新型的孔栅结构,有效地抑制了平行带状线间的耦合干扰。     

铁路工程建设水土流失预测研究

随着铁路建设步伐的加快，铁路建设过程中引起的水土流失问题日益受到重视，以包兰线包头至惠农段电气化改造工程为研究对象，分析了沿线水土流失形式，确定了流失量，并对预测结果进行了总结。     

试论闲暇偏好的效用和对收入分配的影响

提出了闲暇剩余这一概念,并计算了劳动者闲暇偏好对闲暇剩余的影响,同时分析了劳动者闲暇偏好对收入分配不均等性的影响.针对不同群体适当引导对闲暇的偏好,可以满足不同群体的需要,缩小收入差距的不均等性.这对解决我国当前劳动力供需紧张、人们收入差距逐渐拉大具有较强的现实指导意义.     

Minimax estimation of a probability of success under LINEX loss

Minimax estimation of a binomial probability under LINEX loss function is considered. It is shown that no equalizer estimator is available in the statistical decision problem under consideration. It is pointed out that the problem can be solved by determining the Bayes estimator with respect to a least favorable distribution having finite support. In this situation, the optimal estimator and the least favorable distribution can be determined only by using numerical methods. Some properties of the minimax estimators and the corresponding least favorable prior distributions are provided depending on the parameters of the loss function. The properties presented are exploited in computing the minimax estimators and the least favorable distributions. The results obtained can be applied to determine minimax estimators of a cumulative distribution function and minimax estimators of a survival function.     

Simulation of right and left truncated gamma distributions by mixtures

We study the properties of truncated gamma distributions and we derive simulation algorithms which dominate the standard algorithms for these distributions. For the right truncated gamma distribution, an optimal accept–reject algorithm is based on the fact that its density can be expressed as an infinite mixture of beta distribution. For integer values of the parameters, the density of the left truncated distributions can be rewritten as a mixture which can be easily generated. We give an optimal accept–reject algorithm for the other values of the parameter. We compare the efficiency of our algorithm with the previous method and show the improvement in terms of minimum acceptance probability. The algorithm proposed here has an acceptance probability which is superior to e/4.     

概率论在极限问题中的应用

通过建立概率模型、利用概率论相关定理解决了复杂的求极限问题。