A wide area differential backup protection scheme for shipboard application

A new wide area differential protection (WADP) system is proposed to suit the need of the shipboard application where short cables make conventional backup schemes impractical. The close proximity of all the components in a shipboard power system makes communication less of an issue than in a land-based system. With an overall view of the protected system and by use of a differential search algorithm, a minimum fault isolation area is decided. A built-in confirmation mechanism avoids unnecessary or false tripping due to protection component failure. The principle of the WADP system is described in detail in this paper. Simulation results are shown for a small Shipboard Power System (SPS).     

The benefits of active rewarming after cardiac operations: a randomized prospective trial

Studies were carried out to observe the species composition of mosquitos and to determine the vectors responsible for the transmission of filariasis in Grik, Perak, Malaysia. A total of 2,155 mosquitos belonging to 7 genera and 30 species were collected. Anopheles donaldi comprised 24.1% of the collection. Twelve out of 519 An. donaldi were infected with L3 larvae of Brugia malayi. The peak biting time was around 23.00-24.00 hours. The infective bites per month ranged from 0 to 6.3.     

Extensionally defining principles and cases in ethics: An AI model

Principles are abstract rules intended to guide decision-makers in making normative judgments in domains like the law, politics, and ethics. It is difficult, however, if not impossible to define principles in an intensional manner so that they may be applied deductively. The problem is the gap between the abstract, open-textured principles and concrete facts. On the other hand, when expert decision-makers rationalize their conclusions in specific cases, they often link principles to the specific facts of the cases. In effect, these expert-defined associations between principles and facts provide extensional definitions of the principles. The experts operationalize the abstract principles by linking them to the facts.

This paper discusses research in which the following hypothesis was empirically tested: extensionally defined principles, as well as cited past cases, can help in predicting the principles and cases that might be relevant in the analysis of new cases. To investigate this phenomenon computationally, a large set of professional ethics cases was analyzed and a computational model called SIROCCO, a system for retrieving principles and past cases, was constructed. Empirical evidence is presented that the operationalization information contained in extensionally defined principles can be leveraged to predict the principles and past cases that are relevant to new problem situations. This is shown through an ablation experiment, comparing SIROCCO to a version of itself that does not employ operationalization information. Further, it is shown that SIROCCO's extensionally defined principles and case citations help it to outperform a full-text retrieval program that does not employ such information.     

Learning with intelligent tutors and worked examples: selecting learning activities adaptively leads to better learning outcomes than a fixed curriculum

The main learning activity provided by intelligent tutoring systems is problem solving, although several recent projects investigated the effectiveness of combining problem solving with worked examples. Previous research has shown that learning from examples is an effective learning strategy, especially for novice learners. A worked example provides step-by-step explanations of how a problem is solved. Many studies have compared learning from examples to unsupported problem solving, and suggested presenting worked examples to students in the initial stages of learning, followed by problem solving once students have acquired enough knowledge. This paper presents a study in which we compare a fixed sequence of alternating worked examples and tutored problem solving with a strategy that adapts learning tasks to students’ needs. The adaptive strategy determines the type of the task (a worked example, a faded example or a problem to be solved) based on how much assistance the student received on the previous problem. The results show that students in the adaptive condition learnt significantly more than their peers who were presented with a fixed sequence of worked examples and problem solving. Novices from the adaptive condition learnt faster than novices from the control group, while the advanced students from the adaptive condition learnt more than their peers from the control group.     

Supply chain management information systems capabilities. An exploratory study of electronics manufacturers

Supply Chain Management Information Systems (SCM IS) play an increasingly critical role in the ability of firms to reduce costs and increase the responsiveness of their supply chain. This paper develops an empirically supported model of the organizational capabilities enabled by SCM IS. The model integrates and enriches theoretical and empirical studies of competitive strategy, supply chain management, and interorganizational information systems. Evidence from an exploratory case study of three large firms in the electronics manufacturing industry is examined to build a better-supported theory of SCM IS capabilities. The findings suggest the organizational capabilities enabled by SCM IS can be conceptualized as the level of support provided for: operational efficiency; operational flexibility; internal planning and analysis; and external planning and analysis. The theoretical model furthers an understanding of SCM IS capabilities and is sufficiently developed to permit operationalization for future studies evaluating the effectiveness of SCM IS.     

Human sequence learning under incidental and intentional conditions.

This research explored the role that dissociable associative learning and hypothesis-testing processes may play in human sequence learning. Two 2-choice serial reaction time (SRT) tasks were conducted, 1 under incidental conditions and the other under intentional conditions. In both cases an experimental group was trained on 4 subsequences (i.e., XXX, XYY, YYX, and YXY). To control for sequential effects, sequence learning was assayed by comparing their performance to a control group that had been trained on a pseudorandom ordering, during a test phase in which both groups experienced effectively the same trial order. Under incidental conditions participants demonstrated learning of the subsequences that ended in an alternation, but not of those that ended in a repetition. In contrast, under intentional conditions XXX showed the greatest evidence of learning. This dissociation is explained using a 2-process model of learning, with an associative process (the augmented simple recurrent network [SRN]) capturing the incidental pattern, and a rule-based process explaining the advantage for XXX under intentional conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An evaluation of two indirect methods of estimating body weight in Holstein calves and heifers

Monitoring the growth of replacement heifers is a useful management tool to assist producers in achieving a reasonable goal for age at first calving. Standard growth curves have been established, and heart girth tapes are widely available to estimate body weight (BW). Probably the easiest, and undoubtedly the most accurate, means of determining the actual BW of heifers is by using a calibrated electronic scale. However, if an electronic scale is not available, indirect methods of BW estimation are required. The hipometer is a new indirect tool that uses the external width between the greater trochanters of the left and right femurs to estimate BW. The purpose of this observational study was to evaluate the hipometer and the heart girth tape to estimate the BW of Holstein heifers, as compared with their actual weight recorded by an electronic scale. A total of 311 Holstein heifers in 4 research herds, ranging in age from 1 wk old to immediately prior to calving (24 mo), were used in this comparison. The mean BW of all heifers was 261 ± 124 kg. The Pearson values of the correlation between the scale and hipometer weights, and the scale and tape weights were 0.92 and 0.94, respectively. The concordance correlations of scale weight with hipometer and tape weights were 0.98 and 0.99, respectively. The agreement among the 3 methods, as assessed by the kappa statistic, was substantial for heifers aged 3 to 15 mo. However, poor to no agreement was observed in heifers younger than 3 mo, as well as at 15 mo of age or greater (kappa 0 to 0.18). This is of particular concern because these groups represent the age when dairy heifers would be weaned (<3 mo) and the age when breeding would normally commence (>15 mo). We concluded that the hipometer is an easy and useful alternative method of estimating the BW of Holstein heifers, particularly in heifers aged 3 to 15 mo.