Search results for "Opera"
showing 10 items of 8665 documents
The wheel of collaboration tools
2006
Paper from the 2006 20th anniversary conference on Computer supported cooperative work We present a holistic framework for analyzing and specifying collaboration solutions, developed by an oil and gas company in response to practical needs in supporting integrated collaboration and information management. A typology of collaboration tool capabilities, termed the Wheel of Collaboration Tools (WCT), is described. We assess its contributions, and discuss areas of application and potential further development. Our intent is to stimulate discussion and research related to this type of collaboration modeling.
Managing Emerging Information Security Risks during Transitions to Integrated Operations
2010
Paper presented at the 2010 43rd Hawaii International Conference on System Sciences (HICSS). (c) 2010 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works. Paper also available from the publisher: http://dx.doi.org/10.1109/HICSS.2010.260 The Norwegian Oil and Gas Industry is adopting new information communication technology to connect its offshore platforms, onshore control centers and the suppliers. Th…
The Unbalanced Linguistic Aggregation Operator in Group Decision Making
2012
Published version of an article in the journal: Mathematical problems in engineering. Also available from Hindawi: http://dx.doi.org/10.1155/2012/619162 Many linguistic aggregation methods have been proposed and applied in the linguistic decision- making problems. In practice, experts need to assess a number of values in a side of reference domain higher than in the other one; that is, experts use unbalanced linguistic values to express their evaluation for problems. In this paper, we propose a new linguistic aggregation operator to deal with unbalanced linguistic values in group decision making, we adopt 2-tuple representation model of linguistic values and linguistic hierarchies to expres…
A novel identification method for generalized T-S fuzzy systems
2012
Published version of an article from the journal: Mathematical Problems in Engineering. Also available from the publisher:http://dx.doi.org/10.1155/2012/893807 In order to approximate any nonlinear system, not just affine nonlinear systems, generalized T-S fuzzy systems, where the control variables and the state variables, are all premise variables are introduced in the paper. Firstly, fuzzy spaces and rules were determined by using ant colony algorithm. Secondly, the state-space model parameters are identified by using genetic algorithm. The simulation results show the effectiveness of the proposed algorithm
Cooperatives' performance relative to investor-owned firms: a non-distorted approach for the wine sector
2021
PurposeThis study aims to investigate whether significant performance differences between cooperatives and investor-owned firms (IOFs) may exist.Design/methodology/approachBased on data from a sample of Italian wine firms for the period from 2009 to 2018, an adjusted measure of performance called earnings before interests, taxes, depreciations and amortizations gross the raw materials cost was adopted to consider the different objectives of cooperatives relative to those of IOFs.FindingsEmpirical evidence shows that in the context under analysis, cooperatives have performed better than IOFs.Originality/valueDespite the theoretical literature suggesting that the cooperative form of organizat…
Supply chain coordination under asymmetric information and partial vertical integration
2022
AbstractSupply chain contracting is known to suffer from inefficiency in the presence of asymmetric information. Full vertical integration would eliminate the informational inefficiency but can be strategically undesirable. Yet today’s supply chain partnerships exhibit a certain degree of partial vertical integration via equity ties between the firms. Such governance forms received limited attention in supply chain research. Management literature suggests that partial vertical integration may help the firms to ease contracting problems by aligning their incentives, and thus improve the total surplus. We address this proposition by studying a model of a partially integrated supply chain in w…
A Mathematical Model for Equitable In-country COVID-19 Vaccine Allocation
2022
Given the scarcity of COVID-19 vaccines, equitable (fair) allocation of limited vaccines across the main administrative units of a country (e.g. municipalities) has been an important concern for public health authorities worldwide. In this study, we address the equitable allocation of the COVID-19 vaccines inside countries by developing a novel, evidence-based mathematical model that accounts for multiple priority groups (e.g. elderly, healthcare workers), multiple vaccine types, and regional characteristics (e.g. storage capacities, infection risk levels). Our research contributes to the literature by developing and validating a model that proposes equitable vaccine allocation alternatives…
Mixed l-/l1 fault detection observer design for positive switched systems with time-varying delay via delta operator approach
2014
Published version of an article in the journal: International Journal of Control, Automation and Systems. Also available from the publisher at: http://dx.doi.org/10.1007/s12555-013-0466-1 This paper investigates the problem of fault detection observer design for positive switched systems with time-varying delay via delta operator approach. A new fault sensitivity measure, called l-index, is proposed. The l- fault detection observer design and multi-objective l -/l1 fault detection observer design problems are addressed. Based on the average dwell time approach and the piecewise copositive type Lyapunov-Krasovskii functional method in delta domain, sufficient conditions for the existence of …
Forward Kinematic Modelling with Radial Basis Function Neural Network Tuned with a Novel Meta-Heuristic Algorithm for Robotic Manipulators
2022
The complexity of forward kinematic modelling increases with the increase in the degrees of freedom for a manipulator. To reduce the computational weight and time lag for desired output transformation, this paper proposes a forward kinematic model mapped with the help of the Radial Basis Function Neural Network (RBFNN) architecture tuned by a novel meta-heuristic algorithm, namely, the Cooperative Search Optimisation Algorithm (CSOA). The architecture presented is able to automatically learn the kinematic properties of the manipulator. Learning is accomplished iteratively based only on the observation of the input–output relationship. Related simulations are carried out on a 3-Degrees…
Robust adaptive backstepping DP control of ROVs
2022
Dynamic positioning is an important control feature for an underwater remotely operated vehicle. This paper presents a nonlinear dynamic positioning controller suited for application to vehicles with model uncertainties, operating in environments with unpredictable disturbances, such as an aquaculture net cage. The proposed controller combines the backstepping approach with an adaptation term to ensure robustness. Using Lyapunov theory and Matrosov’s theorem the origin of the closed-loop system is proven to be: (i) globally asymptotically stable when assuming persistency of excitation, and (ii) stable and bounded, with the true position converging to the desired position if there is no pers…