Evaluation of the coupled multielectrode array sensor as a real-time corrosion monitor

Coupled multielectrode array sensors made of carbon steel and stainless steels were evaluated and compared with electrochemical noise (EN) sensors. Good correlations between sensor signals and solution corrosivity were observed for all multielectrode array sensors. Some correlation between the average pit index and solution corrosivity was observed for the carbon steel EN sensors, but not for the stainless steel EN sensors. The time-average noise resistances from the stainless steel EN sensors correlate well with solution corrosivity. There were, however, large random fluctuations and drifting for all EN signals, which make the EN sensors unreliable as real-time monitors.     

Mining partial periodic correlations in time series

Recently, periodic pattern mining from time series data has been studied extensively. However, an interesting type of periodic pattern, called partial periodic (PP) correlation in this paper, has not been investigated. An example of PP correlation is that power consumption is high either on Monday or Tuesday but not on both days. In general, a PP correlation is a set of offsets within a particular period such that the data at these offsets are correlated with a certain user-desired strength. In the above example, the period is a week (7 days), and each day of the week is an offset of the period. PP correlations can provide insightful knowledge about the time series and can be used for predicting future values. This paper introduces an algorithm to mine time series for PP correlations based on the principal component analysis (PCA) method. Specifically, given a period, the algorithm maps the time series data to data points in a multidimensional space, where the dimensions correspond to the offsets within the period. A PP correlation is then equivalent to correlation of data when projected to a subset of the dimensions. The algorithm discovers, with one sequential scan of data, all those PP correlations (called minimum PP correlations) that are not unions of some other PP correlations. Experiments using both real and synthetic data sets show that the PCA-based algorithm is highly efficient and effective in finding the minimum PP correlations. Zhen He is a lecturer in the Department of Computer Science at La Trobe University. His main research areas are database systems optimization, time series mining, wireless sensor networks, and XML information retrieval. Prior to joining La Trobe University, he worked as a postdoctoral research associate in the University of Vermont. He holds Bachelors, Honors and Ph.D degrees in Computer Science from the Australian National University. X. Sean Wang received his Ph.D degree in Computer Science from the University of Southern California in 1992. He is currently the Dorothean Chair Professor in Computer Science at the University of Vermont. He has published widely in the general area of databases and information security, and was a recipient of the US National Science Foundation Research Initiation and CAREER awards. His research interests include database systems, information security, data mining, and sensor data processing. Byung Suk Lee is associate professor of Computer Science at the University of Vermont. His main research areas are database systems, data modeling, and information retrieval. He held positions in industry and academia: Gold Star Electric, Bell Communications Research, Datacom Global Communications, University of St. Thomas, and currently University of Vermont. He was also a visiting professor at Dartmouth College and a participating guest at Lawrence Livermore National Laboratory. He served on international conferences as a program committee member, a publicity chair, and a special session organizer, and also on US federal funding proposal review panel. He holds a BS degree from Seoul National University, MS from Korea Advanced Institute of Science and Technology, and Ph.D from Stanford University. Alan C. H. Ling is an assistant professor at Department of Computer Science in University of Vermont. His research interests include combinatorial design theory, coding theory, sequence designs, and applications of design theory.     

Green revolution in electronic displays expected to ease energy and health crises

The technological revolution of long-awaited energy-saving and vision-friendly displays represented by bistable display technology is conning.Here we discuss methods,challenges,and opportunities for implementing bistable displays in terms of molecular design,device structure,further expansion,and required criteria,hopefully benefiting the light-related community.     

An Analysis of SAFER

We investigate some of the algebraic properties of the SAFER block cipher when the message space is considered as a Z -module. In particular, we consider the invariant Z -submodules of the PHT layer and show how these invariant Z -submodules give potential cryptographic weaknesses. Received 12 June 1995 and revised 22 July 1997     

Healthcare foodservice report 1993. Getting ready for reform. Interview by Mitchell Schechter

Hospital foodservice directors & dietitians are facing the greatest challenge of their careers -- to prepare, along with their institutions, for the most thoroughgoing reform of America's healthcare system ever proposed. Healthcare institutions across the country are seeking the means to offer enhanced patient services & gain competitive advantages by forming new alliances, new patient-centered care systems & cost-reduction programs. To aid in these efforts, their foodservices are developing comprehensive cross-training schemes, inter-departmental teams with other service groups & new ways to cut operating subsidies. Here's how five hospital foodservice departments are using cost controls, revenue building, quality management processes & enhanced efficiencies to help their institutions prepare for the changes ahead.     

New techniques for commercial bread dough mixing

Bread dough mixing is a complex and uncertain process that involves both biological and mechanical polymerization. Although a human expert can control the mixing of dough, it is difficult to model mathematically for use in a conventional control schema. Using the results of the well-known mixograph test for gluten development, expert bakers have observed that the instantaneous mechanical power needed to mix dough has a significant relationship with the dough's gluten development and hydraulic absorption. A logical conclusion based on this observation is to measure the input electrical power for automatic control of large dough mixers. Such a control system must sense the instantaneous, three-phase input power; this signal is very noisy, nonlinear, nonstationary, and time varying. Hence, fuzzy logic is a good tool for developing an automatic control system. Such a system is described     

先进服务器应用的内存解决方案

内存性能对于桌上型计算机、路由器,甚至是个人数字助理(PDA)已是基本要求,对服务器与工作站而言,更为重要.由于需要处理密集运算工作置及管理大量数据,系统就必须配置最先进的内存.     

Extending the threshold and frequency range for phase-basedfrequency estimation

Standard phase-based frequency estimation has a threshold that is high, is frequency dependent, and does not decrease with increasing signal length. These problems are solved by processing the signal with a highly overlapped filter bank before applying phase-based frequency estimation. By exploiting decimation, a closed-form matrix inversion, and cascades of simple filter banks, the computational complexity is kept low