92 research outputs found

    Implementation of Secure DNP3 Architecture of SCADA System for Smart Grids

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    With the recent advances in the power grid system connecting to the internet, data sharing, and networking enables space for hackers to maliciously attack them based on their vulnerabilities. Vital stations in the smart grid are the generation, transmission, distribution, and customer substations are connected and controlled remotely by the network. Every substation is controlled by a Supervisory Control and Data Acquisition (SCADA) system which communicates on DNP3 protocol on Internet/IP which has many security vulnerabilities. This research will focus on Distributed Network Protocol (DNP3) communication which is used in the smart grid to communicate between the controller devices. We present the DNP3 SAv5 and design a secure architecture with Public Key Infrastructure (PKI) on Asymmetric key encryption using a Certificate Authority (CA). The testbed provides a design architecture between customer and distribution substation and illustrates the verification of the public certificate. We have added a layer of security by giving a password to a private key file to avoid physical tampering of the devices at the customer substations. The simulation results show that the secure communication on the TLS layer provides confidentiality, integrity, and availability

    Empowerment: a Necessary Attribute of a Learning Organization?

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    Purpose: The purpose of this paper is to study the role of empowerment in a learning organization. This research tries to explore whether empowerment is a necessary attribute for organizations to enhance their learning capability or not. It attempts to address two fundamental questions:• What is the role of empowerment in an organization’s learning capability?• Is empowerment an essential attribute of a learning organization?Methodology: The study adopted a mixed method of research design, which includes both qualitative and quantitative methods of data collection and analysis. The quantitative survey comprised of two questionnaires was used to survey 213 executives from various IT organizations. Interviews were also conducted with executives of two case organizations where in-depth study was conducted. Qualitative data was analyzed using the grounded theory methodology.Findings: The findings indicate that only the decision making dimension of empowerment has emerged as a significant predictor of organizational learning, not the power sharing and people valuing dimensions. Further, no difference is observed in high and low learning organizations on their empowerment pattern.Research Limitations/Implications: The sample organizations were from one geographical location (National Capital Region) of India and the study was conducted in the IT sector only. Future studies may investigate this further in different regions and sectors

    Modelling complex livestock-agricultural systems at a regional scale : A case study in La Reunion

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    Réunion Island, situated in the Indian Ocean, presents a unique case study to model regional bio-economic parameters of the dairy industry. It is a good example of a closed system for movement of animals, available labour, consumption of products, and available land. The present study models the dairy sector at a regional (island) level, in close collaboration with key stakeholders, to study the impact of new agricultural policies in terms of changes to subsidy norms, price fluctuations and environment, with reference to nitrogen excess. The model can be used to generate a number of scenarios, to explore the effects of various industry controls, such as fixing the stocking rate according to EU norms, increasing or reducing the milk subsidy, intensification (such as an increase in milk production to 40 million litres per year) and labour and price constraints (such as an increase or reduction in the milk price or a reduction in labour hours). The model is being consulted by the local dairy cooperative as a discussion support tool at a regional scale to look at implications of expanding the sector and its economic, environmental and social impact. (Résumé d'auteur

    Combining interactive multiple goal linear programming with an inter-stakeholder communication matrix to generate land use options

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    An Interactive Multiple Goal Linear Programming (IMGLP) model is developed that considers objectives of multiple stakeholders, i.e. different farmer groups, district agricultural officers and agricultural scientists for agricultural land use analysis. The analysis focuses on crop selection; considering irrigated and non-irrigated crops such as rice, sugarcane, sorghum, cotton, millet, pulses and groundnut. Interests of the most important stakeholders, farmers, policy makers and water users association are investigated. Important objectives of the farmers are increased income and retaining paddy area; of the policy makers (Agricultural Department) increased farmers’ income, maintaining rural employment, improve water-use efficiency, reduce fertiliser and biocide use and discourage farmers from cultivating marginal lands; of the water users association optimising water use. Scenarios have been constructed by combining objectives and constraints. A Stakeholder Communication Matrix (SCM) indicating the level of communication and information flow among stakeholders in the district was generated after a Participatory Rural Appraisal (PRA). Results of the scenarios generated with the IMGLP model were compared with the matrix. The relevance of analysing the results of the scenarios generated with the IMGLP model in the context of the SCM is illustrated for a sample set of scenarios. Scenario 1 (S1), where both the paddy area and the agricultural area are retained at the current level, is preferred by the farmers. However, the Agricultural Department would identify more easily with S10 in which the paddy area is reduced by 50% and the agricultural area by 20%, in accordance with the policy of limiting the area of high water-demanding crops and dissuading farmers from cultivating marginal lands, while the water users association would prefer S12, where water use is minimised by expanding the area of crops that are relatively less water-demanding. Income in S12 is 22% lower than in S1, while water use is 36% lower, and there is a significant reduction in biocide use. The conflict between S1 and S10 is compounded by the fact that communication between small-scale farmers and the Agricultural Department is relatively weak. Analysing the scenarios in the context of the SCM is useful to gain insight into the interactions among stakeholders in the system and take curative measures if required for improved communication. While the IMGLP model considers the bio-economics of the land use system, the SCM describes its social aspects, which may be critical for successful implementation of the IMGLP model

    A comparative study of fractional order PIλ /PIλ Dμ tuning rules for stable first order plus time delay processes

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    Conventional PID tuning methods may not be sufficient to deal with complex processes of modern industry. For better control, fractional order PIλDµ controller was introduced as the generalization of classical PID controller with the help of non-integer order (fractional order) calculus. The fractional calculus uses integration and differentiation with a fractional order or complex order. The major advantage of fractional derivative is the ability to inherit the nature of the processes. In general, the control loop includes both fractional order process model and fractional order controller. However, the processes to be controlled are usually modeled as integer order models and controlled using fractional order controllers. But if the plant model is obtained as fractional model, it is converted into integer order model by approximating the fractional terms using different approximations proposed in the literature. With all the above mentioned advantages, several fractional order PIλ/PIλDµ tuning rules are proposed in the literature for integer order systems and researchers are still proposing the new rules. The main aim of this paper is to compare fractional order PI/PID tuning methods based on Integral of Absolute Error (IAE), Total Variation (TV) and Maximum Sensitivity (Ms). The main reason for choosing fractional order PIλ/PIλDµ controllers is their additional degrees of freedom that result in better control performance. These tuning rules were applied on several first order plus time delay processes subjected to step change in setpoint and disturbance
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