A Class of Algorithms for Collision Resolution with Multiplicity Estimation

The wireless connectivity in pervasive computing has ephemeral character and can be used for creating ad hoc networks, sensor networks, connection with RFID (Radio Frequency Identification) tags etc. The communication tasks in such wireless networks often involve an inquiry over a shared channel, which can be invoked for: discovery of neighboring devices in ad hoc networks, counting the number of RFID tags that have a certain property, estimating the mean value contained in a group of sensors etc. Such an inquiry solicits replies from possibly large number of terminals n. This necessitates the usage of algorithms for resolving batch collisions (conflicts) with unknown conflict multiplicity n. In this paper we present a novel approach to the problem of collision resolution for batch conflicts. We show how the conventional tree algorithms for collision resolution can be used to obtain progressively accurate estimation of the multiplicity. We use the estimation to propose a more efficient binary tree algorithm, termed Estimating Binary Tree (EBT) algorithm. The EBT algorithm is suited for implementation when the conflicting nodes are passive, such as e.g. RFID tags. We extend the approach to design the Interval Estimation Conflict Resolution (IECR) algorithm. For n→∞ we prove that the efficiency achieved by IECR for batch arrivals is identical with the efficiency that Gallager’s FCFS algorithm achieves for Poisson packet arrivals. For finite n, the simulation results show that IECR is, to the best of our knowledge, the most efficient batch resolution algorithm reported to date.     

The Strategic Control of Multiple Routes in Imitation of Actions.

The aim of this study was to bring to the surface the strategic use of imitative processes in the context of a 2-route model: (a) direct imitation, used in reproducing new, meaningless actions, and (b) imitation based on stored semantic knowledge of familiar meaningful actions. Three experiments were carried out with healthy participants who reproduced meaningful and meaningless actions within an established time limit. The study investigated 3 factors that could potentially affect the selection of processes used for imitation: (a) the composition of the experimental list (blocked or mixed presentation), (b) the presence-absence of instructions (Experiments 1 and 2), and (c) the relative proportions of the stimuli (Experiment 3). Overall, the results suggest that each of these factors influences the selection of imitative strategies in healthy individuals with temporarily reduced capacities, as happens in the case of brain-damaged patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

炼制进口原油常减压装置的腐蚀问题

胜利炼油厂第三常减压装置改炼进口高硫原油或进口原油掺炼陆上原油后 ,设备腐蚀明显加重 ,致使换热器E2 4/ 1和空冷器A1/ 1腐蚀率高达 2 .5mm/a。腐蚀加重的主要原因是由于原油脱后盐含量偏高 ( 10～ 2 0mg/L)、硫含量高 ( 1.5 %～ 2 .5 % )所造成的塔顶及其冷凝冷却系统H2 S -HCl-H2 O环境的腐蚀 ,高温重油部位则主要是环烷酸引起的腐蚀。同时提出了改造电脱盐系统、优化原油调配和加强注剂管理等一系列措施     

Linkages between spouses' psychological distress and marital conflict in the home.

To elucidate the processes that underlie the established association between psychopathology and marital functioning, researchers have given attention to how symptomatic individuals manage their interpersonal contexts, particularly during the handling of disagreements. In the current study, the authors evaluate the role of marital conflict strategies in relation to wives' and husbands' psychological distress levels. A sample of 100 community-based couples completed assessments of psychological distress and diaries describing marital conflict that occurred at home during a 15-day reporting period. Findings from multilevel modeling of dyadic data revealed associations between both spouses' psychological distress and multiple behavioral and emotional conflict expressions in the home. Psychological symptoms uniquely predicted the occurrence of certain conflict expressions, even when accounting for global negative marital sentiments. The findings encourage subsequent consideration of marital conflict expressions and resolution strategies when studying processes involved in the marriage-psychological adjustment link. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Siblings' differential experiences of marital conflict and differences in psychological adjustment.

The present study examined whether siblings experience marital conflict differently and whether such differences, if present, were associated with differences in their adjustment. Self-report data about marital conflict, children's depressed mood, behavioral conduct, and externalizing problems were obtained from 122 sibling pairs (mean ages = 10 and 12 years) and their parents. Results indicated that siblings were significantly different in exposure to and appraisals of marital conflict. Differences in siblings' exposure to marital conflict were significantly correlated with differences in their depressed mood, behavioral conduct, and externalizing problems. Differences in siblings' feelings of self-blame for marital conflict were significantly correlated with differences in their depressed mood and behavioral conduct. Children who experienced more marital conflict than their siblings had more adjustment problems than their siblings. These results highlight the importance of studying siblings' unique experiences of marital conflict to better understand its impact on children's adjustment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

改进的BP神经网络在大坝安全监控中的应用

针对经典BP神经网络运行中存在的缺陷，提出了改进的BP神经网络，不仅解决了经典BP网络易陷入局部最小的弊端，而且应用的0.618分割选取法能使网络快速找到较优隐含层节点数，初始权值的自相关修正进一步提高了网络的稳定性。实际应用证明，改进的BP神经网络有效提高了网络质量，适合大型网络的构建与训练。     

醋酸的腐蚀及其结构材料选用探讨

醋酸是重要的化工产品之一，但醋酸的腐蚀严重影响了设备的安全稳定运行。醋酸选材应考虑其氧化性与还原性，特别是氧化剂与卤素离子等杂质的综合影响。对不锈钢、钛、镍基合金与铜等各种材料的应用作了评析。     

结构工艺性冲突解决策略的研究

通过分析各种冲突解决方法的特点，提出了一种冲突的集成解决方案。采用面向对象的Object Pascal语言编制了一个实例，给出了该方法在零件结构工艺性设计中的具体应用。     

Differences in Dialysis Practice Are the Main Reasons for the High Mortality Rate in the United States Compared to Japan

The cumulative survival of Japanese hemodialysis patients is more than 2.5 times better than that of dialysis patients in the United States (U.S.). The difference is particularly pronounced in older patients, being 4 times better in patients over the age of 50 years. The mortality in U.S. patients has increased from 10 to 25% over the last three decades, but has remained stable at around 10% in Japan.
There is no obvious difference in patient selection. The Japanese accept almost as high a proportion of diabetic patients as does the United States, and the mean age of incident patients is higher in Japan.
Renal transplantation, virtually absent in Japan, should increase mortality in U.S. dialysis patients by removing patients with the highest probability of survival, but even if one adds surviving transplant patients and studies prevalent populations, the survival rate is much better in Japan. Genetic factors are unlikely to explain differences in mortality, as older Americans live much longer than older Japanese.
We speculate that the difference lies in the practice of dialysis. Patients in the United States are generally treated by much faster and shorter dialysis than in Japan. This puts a severe burden on the cardiovascular system of older patients, leading to the poorer survival rate. Japanese physicians also appear to be better trained in dialysis and to spend more time with their patients. The nursing shortage in the United States may also contribute to the increased mortality. Whatever the explanations, the U.S. dialysis community must work to equal and, hopefully, surpass the now superior survival of Japanese dialysis patients.