Intelligent interaction in diagnostic expert systems

AbstractAdvisory systems help to improve quality in manufacturing. Such systems, however, both human and computerized, are less than perfect and frequently not welcome. Sharp separation between working and learning modes is the main reason for the apparent hostility of advisory systems. Intelligent interaction deploys computerized advisory capabilities by merging working and learning modes. We have developed a knowledge-based interactive graphic interface to a circuit pack diagnostic expert system. The graphic interface integrates both the domain knowledge (i.e. circuit pack) and the troubleshooting knowledge (i.e. diagnostic trees). Our interface dynamically changes the amount of detail presented to the user as well as the input choices that the user is allowed to make. These changes are made using knowledge-based models of the user and of the circuit pack troubleshooting domain. The resulting system, McR, instead of guiding the user by querying for input, monitors users actions, analyzes them and offers help when needed. McR is able both to advise “how-to-do-it” by reifying shallow knowledge from the deep knowledge, and to explain intelligently “how-does-it-work” by abstracting deep knowledge from the hallow knowledge, McR is used in conjunction with the STAREX expert sytem which is installed at AT&T factory

A Clinical Profile of 50 cases of Hypoglycemia in a Tertiary Care Hospital

Hypoglycemia is defined as a blood glucose level/dl. It is usually seen in Diabetics due to an improper balance between blood glucose-lowering drugs and food. Patients can have various symptoms, ranging from headaches and palpitations to coma and death. Patients are typically treated with oral carbohydrates and IV carbohydrates/Glucagon if needed. It is essential to understand the presenting complaints of Hypoglycemia as it often complicates the management of Diabetic patients, and sometimes non-Diabetic patients. The symptoms may frequently be mild but can cause significant long-term complications. It is also essential to understand the cause of Hypoglycemia in order to prevent future episodes. In this case series, we describe 50 cases – their presenting complaints, Capillary Blood Glucose (CBG) values, and likely causes for the events. We also describe the management as done in our hospital

Renewable energy based microgrid system sizing and energy management for green buildings

The objective of this paper is to model a hybrid power system for buildings, which is technically feasible and economically optimal. With a view to promote renewable energy sources, photovoltaics and wind turbines are integrated with the grid connected building. The system is modeled and the optimal system configuration is estimated with the help of hybrid optimization model for electric renewables (HOMER). The logic is illustrated with a case study based on the practical data of a building located in southern India. This building is associated with 3.4 MWh/day priority load (peak load as 422 kW), as well as 3.3 MWh/day deferrable load (peak load as 500 kW). Sensitivity analysis is performed to deal with uncertainties such as the increase in electricity consumption and grid tariff, environmental changes, etc. From the simulation result, it is observed that the designed system is cost effective and environment friendly, which leads to 6.18 % annual cost savings and reduces CO2 emissions by 38.3 %. Sensitivity results indicate that the system is optimal and adaptable in a certain range of unanticipated variances with respect to best estimated value. Finally, an energy management strategy is developed for the optimal system to ensure reliable power during contingency and disturbances. The green and hybrid power system designed can be adaptable to any critical and large consumers of urban buildings

Key Aspects of Smart Grid Design for Distribution System Automation: Architecture and Responsibilities ☆

In the conventional distribution network, systems designed for the control of individual constituents are autonomous with each other with respect to architectures and controlling. Thus, centralized control and integrated functionality are the major challenges faced by the distribution system operators. To overcome these issues, the term “distribution system automation” came into picture by using information and communications technology (ICT)as a resolution that integrate all the critical constituents of a distribution system. This develops a smart environment at power distribution level, called as “smart microgrid” that can optimize the system economy and improve the system resiliency. The major challenge lies in distribution system automation is the selection of proper architecture and communications. In view of all these aspects, this paper present an overview of distribution system automation as a part of smartgrid initiatives and its important features viz., architecture layout and responsibilities

Stable and Metastable vortex states and the first order transition across the peak effect region in weakly pinned 2H-NbSe_2

The peak effect in weakly pinned superconductors is accompanied by metastable vortex states. Each metastable vortex configuration is characterized by a different critical current density J_c, which mainly depends on the past thermomagnetic history of the superconductor. A recent model [G. Ravikumar, et al, Phys. Rev. B 61, R6479 (2000)] proposed to explain the history dependent J_c postulates a stable state of vortex lattice with a critical current density J_c^{st}, determined uniquely by the field and temperature. In this paper, we present evidence for the existence of the stable state of the vortex lattice in the peak effect region of 2H-NbSe_2. It is shown that this stable state can be reached from any metastable vortex state by cycling the applied field by a small amplitude. The minor magnetization loops obtained by repeated field cycling allow us to determine the pinning and "equilibrium" properties of the stable state of the vortex lattice at a given field and temperature unambiguously. The data imply the occurence of a first order phase transition from an ordered phase to a disordered vortex phase across the peak effect.Comment: 20 pages, 10 figures. Corresponding author: S. Ramakrishna

Dynamic pricing models for electronic business

Dynamic pricing is the dynamic adjustment of prices to consumers depending upon the value these customers attribute to a product or service. Today’s digital economy is ready for dynamic pricing; however recent research has shown that the prices will have to be adjusted in fairly sophisticated ways, based on sound mathematical models, to derive the benefits of dynamic pricing. This article attempts to survey different models that have been used in dynamic pricing. We first motivate dynamic pricing and present underlying concepts, with several examples, and explain conditions under which dynamic pricing is likely to succeed. We then bring out the role of models in computing dynamic prices. The models surveyed include inventory-based models, data-driven models, auctions, and machine learning. We present a detailed example of an e-business market to show the use of reinforcement learning in dynamic pricing

Unusual C–C Bond Cleavage in the Formation of Amine-Bis(phenoxy) Group 4 Benzyl Complexes: Mechanism of Formation and Application to Stereospecific Polymerization

Group 4 tetrabenzyl compounds MBn4 (M = Zr, Ti), upon protonolysis with an equimolar amount of the tetradentate amine-tris(phenol) ligand N[(2,4-tBu2C6H2(CH2)OH]3 in toluene from −30 to 25 °C, unexpectedly lead to amine-bis(phenoxy) dibenzyl complexes, BnCH2N[(2,4-tBu2C6H2(CH2)O]2MBn2 (M = Zr (1), Ti (2)) in 80% (1) and 75% (2) yields. This reaction involves an apparent cleavage of the >NCH2–ArOH bond (loss of the phenol in the ligand) and formation of the >NCH2–CH2Bn bond (gain of the benzyl group in the ligand). Structural characterization of 1 by X-ray diffraction analysis confirms that the complex formed is a bis(benzyl) complex of Zr coordinated by a newly derived tridentate amine-bis(phenoxy) ligand arranged in a mer configuration in the solid state. The abstractive activation of 1 and 2 with B(C6F5)3·THF in CD2Cl2 at room temperature generates the corresponding benzyl cations {BnCH2N[(2,4-tBu2C6H2(CH2)O]2MBn(THF)}+[BnB(C6F5)3]− (M = Zr (3), Ti, (4)). These cationic complexes, along with their analogues derived from (imino)phenoxy tri- and dibenzyl complexes, [(2,6-iPr2C6H3)N═C(3,5-tBu2C6H2)O]ZrBn3 (5) and [2,4-Br2C6H2(O)(6-CH2(NC5H9))CH2N═CH(2-adamantyl-4-MeC6H2O)]ZrBn2 (6), have been found to effectively polymerize the biomass-derived renewable β-methyl-α-methylene-γ-butyrolactone (βMMBL) at room temperature into the highly stereoregular polymer PβMMBL with an isotacticity up to 99% mm. A combined experimental and DFT study has yielded a mechanistic pathway for the observed unusual C–C bond cleavage in the present protonolysis reaction between ZrBn4 and N[(2,4-tBu2C6H2(CH2)OH]3 for the formation of complex 1, which involves the benzyl radical and the Zr(III) species, resulting from thermal and photochemical decomposition of ZrBn4, followed by a series of reaction sequences consisting of protonolysis, tautomerization, H-transfer, oxidation, elimination, and radical coupling

Secondary peak on asymmetric magnetization loop of type-II superconductors

Asymmetric magnetization loops with a second peak effect were parameterized by the extended critical state model. The magnetic field distribution in a sample is considered. Expression is suggested for a peak of the critical current density and corresponding depression on field dependence of the depth of surface layer with equilibrium magnetization. These functions determine the width and the asymmetry of a magnetization loop. Asymmetry of the secondary peak height on magnetization branches for increasing and decreasing field is reproduced on the computed magnetization curves.Comment: 6 pages, 2 figures, Equation 6 is modified to be f=0 at B=

Critical depinning force and vortex lattice order in disordered superconductors

We simulate the ordering of vortices and its effects on the critical current in superconductors with varied vortex-vortex interaction strength and varied pinning strengths for a two-dimensional system. For strong pinning the vortex lattice is always disordered and the critical depinning force only weakly increases with decreasing vortex-vortex interactions. For weak pinning the vortex lattice is defect free until the vortex-vortex interactions have been reduced to a low value, when defects begin to appear with a simultaneous rapid increase in the critical depinning force. In each case the depinning force shows a maximum for non-interacting vortices. The relative height of the peak increases and the peak width decreases for decreasing pinning strength in excellent agreement with experimental trends associated with the peak effect. We show that scaling relations exist between the distance between defects in the vortex lattice and the critical depinning force.Comment: 5 pages, 6 figure