Abstract

State-of-the-art adaptive or robust adaptive techniques for several classes of uncertain switched systems demand structural knowledge of the system dynamics in order to appropriately select the regressor terms in the adaptive law. As a result, the number of unknown parameters to be adapted increases with system complexity, which can lead to very complex adaptive laws. In this work we propose, for the relevant class of Euler-Lagrange systems subject to time-dependent slow switching, a switched robust adaptive control framework with reduced complexity: the number of unknown parameter to be adapted is independent on the system complexity, whereas the regressor terms in the adaptive laws do not require any structural knowledge of the system dynamics. Stability analysis is provided to illustrate the benefit of the proposed design, and the performance of the controller is verified using a switched system stemming from the combination of mooring and free-hanging operations in dynamic positioning of offshore ships

Abstract

This work presents a Lyapunov-based approach to adaptive control of uncertain Euler-Lagrange (EL) systems in a slow switching scenario. Fundamental trade-offs arising from considering uncertain dynamics with unknown uncertainty bounds are presented and discussed. Contrary to the nonswitched scenario, the use of acceleration feedback seems to be unavoidable in the switched scenario: this is due to the fact that an acceleration feedback and an appropriate Lyapunov function must be adopted to make the switching law independent from the unknown uncertainty bounds. In the absence of such feedback or using different Lyapunov functions, a stabilizing switching law would exist but could not be determined as it would depend on an unknown uncertainty bound.

Abstract

Periodic-frequent pattern mining is an important model in data mining. The popular adoption and successful industrial application of this model has been hindered by the following two limitations: (i) The periodic-frequent pattern model implicitly assumes that all transactions within the data occur at a uniform time interval. This assumption limits the model’s applicability as the transactions in many real-world databases occur at irregular time intervals. (ii) Finding periodic-frequent patterns in very large databases is a memory intensive process because its mining algorithm has to maintain a list structure to record all timestamps at which an itemset has appeared in the whole data. This paper makes an effort to address these two limitations. A flexible model of periodic-frequent pattern in temporal databases has been described to address the former issue. In order to address the latter issue, a novel concept known as period summary has been introduced to effectively capture the temporal occurrence information of an itemset in a database. A new tree structure, called Periodic Summary-tree (PS-tree), has be introduced to record the temporal occurrence information of an itemset in a temporal database. A patterngrowth algorithm has also been described to find all periodic-frequent patterns from PStree. Experimental results demonstrate that the proposed algorithm is efficient.

Abstract

The coffee white stem borer (CWSB), Xylotrechus quadripes (Coleoptera: Cerambycidae), is a major pest of arabica coffee causing considerable losses to the growers and its control has been an issue of significance in the pest management. Among the integrated management strategies, spraying of Chlorpyrifos 20EC at appropriate time will prevent the development of pest. This study was aimed to find out the alternative chemical for Chlorpyrifos 20EC which is being used for more than a decade. The laboratory experiments indicated that insecticides like Phenthoate 50EC, Fipronil 5SC, Thiamethoxam 12.6 + Lambda-Cyhalothrin 9.5 ZC, Chlorpyrifos 50EC + Cypermethrin 5EC and Chlorpyrifos 20EC caused 100% mortality of eggs and it is significantly on par with Ethioprole + Imidacloprid 80WG (98%). In case of neonate larvae, 100 percent mortality was observed in the treatments viz., Phenthoate 50EC, Imidacloprid 17.8SL, Fipronil 5SC, Thiamethoxam 12.6 + Lambda-Cyhalothrin 9.5% ZC, Ethioprole + Imidacloprid 80 WG, Chlorpyrifos 50EC + Cypermethrin 5EC and Chlorpyrifos 20EC. The least mortality was observed in Indoxacarb 14.5 SC among the insecticides tested. The field experiment data revealed that maximum ovicidal and larvicidal action was observed to Chlorpyrifos 50EC + Cypermethrin 5EC and Chlorpyrifos 20EC followed by Phenthoate 50EC and Fipronil 5SC. The least mortality of eggs and neonate larvae was recorded to Novaluron 10 EC and Indoxacarb 14.5 SC. It is, therefore, Chlorpyrifos 50EC + Cypermethrin 5EC, can be utilized as a valuable alternate for Chlorpyrifos 20EC in integrated management of coffee white stem borer.

Abstract

The studys objective was to measure the somatic state response (skin conductance and heart rate) and understand the decision making processes in a two-player Centipede game, an extensive form game, with a modified payoff. The experiment included fixed and random termination for analyzing the effect of players mutual trust on risk-taking behavior. The behavioral results reveal that trust controls the game rounds (that is, the number of pass decisions) in known or random termination game conditions, though the exit points were higher in the former compared to the latter condition. Higher skin conductance and heart rate during the game-play is noticed as compared to the baseline data showing anxiety during the gameplay and interestingly opponents action induced higher skin conductance amplitude than during self-play for the same decision. The data provides strong preliminary evidence of trust influencing cooperative gameplay.

Abstract

Analytic reasoning differences, as gauged from intelligence metrics, in students engaged in streams requiring a predominantly divergent (arts) or convergent thinking (science and engineering) is a topic of interest. In this paper we have examined this difference by a modified sequence of two sections (D & E) of the Standard Ravens Progressive matrices (RPM). The scan path gaze behavior was analyzed with an eye tracker. The 30 engineering students (half of them are also trained in fine arts) scored higher than the 15 fine arts students. In the former cohort, the artistic and the non-artistic set show no difference in performance but the scan path, fixation count and time taken indicate possible differences in visual strategies for pattern identification. From the detailed analysis, we argue that intelligence as measured by RPM is enhanced by training in reasoning and logic as in engineering streams and might not reflect an innate ability

Abstract

High utility itemset mining is an important model with many real-world applications. But the popular adoption and successful industrial application of this model has been hindered by the following two limitations: (i) computational expensiveness of the model and (ii) infrequent itemsets may be output as high utility itemsets. This paper makes an effort to address these two limitations. A generic high utility-frequent itemset model is introduced to find all itemsets in the data that satisfy user-specified minimum support and minimum utility constraints. Two new pruning measures, named cutoff utility and suffix utility, are introduced to reduce the computational cost of finding the desired itemsets. A single phase fast algorithm, called High Utility Frequent Itemset Miner (HU-FIMi), is introduced to discover the itemsets efficiently. Experimental results demonstrate that the proposed algorithm is efficient.

Abstract

Honking in traffic is an auditory warning to indicate: driver’s actions, alert pedestrians and to convey an emergency situation requiring right of way. Though studies have shown the importance of honking in maintaining traffic flow, there have been cases where irrational use leads to an increase in stress/irritation with effects on driver decision making. Most drivers are unaware of the adverse health effects of high decibel honking. In this report, we looked at the effects of honking on driving behavior in a lab-developed VR driving simulator and anxiety/stress as indicated by changes in skin conductance /pulse rate measured using sensors.

Abstract

In real-world databases, high utility itemset (HUI) is an important class of regularities. Most previous studies have focused on mining HUIs in transactional databases and did not consider the spatiotemporal characteristics of items. In this study, a more flexible model of spatial HUIs (SHUIs) that exist in spatiotemporal databases is proposed. In a spatiotemporal database (STD), an itemset is said to be an SHUI if its utility is not less than a user-specified minimum utility and the distance between any two of its items is not more than a user-specified maximum distance. Identifying SHUIs is very challenging because the generated itemsets do not satisfy the anti-monotonic property. In this study, we present two novel pruning techniques for reducing computational costs. Moreover, a fast single scan algorithm is presented for effectively evaluating all SHUIs in a STD. Furthermore, two case studies are presented, in which the proposed model is used to identify useful information in traffic congestion data and air pollution data.

Abstract

In retail stores, the placement of items on the shelf space significantly impacts the sales of items. In particular, the probability of sales of a given item is typically considerably higher when it is placed in a premium (i.e., highly visible/easily accessible) slot as opposed to a non-premium slot. In this paper, we address the problem of maximizing the revenue for the retailer by determining the placement of the itemsets in different types of slots with varied premiumness such that each item is placed at least once in any of the slots. We first propose the notion of premiumness of slots in a given retail store. Then we discuss a framework for efficiently identifying itemsets from a transactional database and placing these itemsets by mapping itemsets with different revenue to slots with varied premiumness for maximizing retailer revenue. Our performance evaluation on both synthetic and real datasets demonstrate that the proposed scheme indeed improves the retailer revenue by up to 45% w.r.t. a recent existing scheme.