A formal framework to integrate express data models in an extended enterprise context

The paper describes a formal framework to integrate EXPRESS models and facilitate sharing and exchanging of data in an Extended Enterprise context. We perceive in the creation of an Extended Enterprise an opportunity to use standardized data models. Hence our research is based on three important ISO standards whose primary objective is to enhance data exchange. These standards are ISO 10303, ISO 15531 and ISO 13584, known as STEP, MANDATE and PLIB, respectively. Although they are intended to overcome incompatibility problems for the computer-based applications that are used during the product life-cycle, they turned out to be semantically incompatible among themselves. This seems to be a major drawback when individual organizations want to share core competences, such as resources, manufacturing processes, or product design, to create an Extended Enterprise. The constructs we propose harmonize incompatible model components so that core competences can be transparent to the net of enterprises. The proposal is exemplified by creating a mediator application and a repository. The mediator application is used by individual firms to gain access to the core abilities that are shared, whereas the repository is a neutral means to store such competences. It complies with part 21 of the ISO 10303 standard. The proposed formal framework provides a sound model of the information system and facilitates data sharing in the Extended Enterprise.     

Knowledge, power and action: towards an understanding of implementation failures in a government scheme

Conceptual knowledge inspires imagination. On the other hand, it is a claim to power as well. Multiple knowledge claims often, therefore, are engaged in a contest. This contest can take the form of several discourses. Extant power structures play a significant role in lending (or not lending) a voice to one or several such discourses. To one with the power to govern, knowledge claims flowing from abstract concepts generated in an elite discourse not only inspires imagination but also often leads to ‘norms’ and ‘rules’ that drive governance in the system which leads to action. Norms and rules define actionability of the conceptual knowledge claim. However, for the one weighed by powerlessness in being governed, knowledge claims often get generated only in action, since an autonomous discourse is often lacking. Yet the sheer powerlessness of the authors of such knowledge claims generated in action leads to its non-celebration. It fails to get elevated. It might also wither away. Such actionable knowledge claims of the powerless often then gets manifested as something like an ‘unvoiced’ or an ‘unvoicable’ discourse, in macabre forms of subversion of ‘norms’ and ‘rules’ of the system that leads to a sense of failure in governance among those with power as well. Power, thus, brings actionable knowledge to the fore, but in two different forms. For the power-holder, it takes the form of a ‘deviation’ from norms and rules in the actionable domain through subversion by the powerless, revealing a gap between knowledge in the conceptual and actionable domain that is reluctantly (often tacitly) tolerated. For the powerless, on the other hand, actionable knowledge is living; negotiating on the ‘deviation’ is an existential requirement. This paper is an attempt to explore these dichotomies, how power (and the lack of it) alters the significance and implications of actionable knowledge.     

Effect of Size Parameters of Mix Ingredients on the Porosity and Reduction Characteristics of Sinter

The paper aims to describe the effect of size parameters of the mix ingredients on the tumbler index, porosity and reduction properties of sinter. These parameters are important factors for the furnace performance when the sinter is fed as burden material Understandably, the fines generated inside the furnace in the stack zone or during reduction affect the permeability of the stack zone, which results in a decrease in driving rate and CO utilisation. Pot sintering studies were carried out using hematite ore mix from typical mines in India. The sinter basicity (CaO/SiO₂) and MgO content in the sinter were kept at 2.1 and 1.5% respectively. The effect of the size parameters of the mix ingredients, namely size of coke, size of ore fines and that of limestone, on the porosity and quality parameters of sinter was investigated. The studies have shown that reducibility of sinter was well correlated with the proportion of micro‐pores out of total pores available in the sinter. Micro‐porosity of the sinter samples and their reducibility increased with decrease in the size range of coke breeze. Sintering of ore fines with reduced size, also, increased the sinter micro‐porosity. Besides, the average pore radius and density of the sinter sample and consequently the sinter reducibility increased with decreasing ore size. When the size of flux was narrowed down to –3+0.5 mm from –3 mm, the reduction degradation index value declined from 26.8% to 25.6% with marginal decrease in sinter reducibility. Moreover, the speed of sintering increased as well.     

Bounds on performance for the noisy reference PSK channel

A lower bound is derived for the uncoded error probability of coherent digital phase-shift-keying without making any assumptions on phase-locked loop speed. An improved upper bound on bit error probability is also derived. The results are applicable to both lightwave homodyne detection, in which the laser's phase noise must be taken into account, and to general partially coherent detection of (binary phase-shift-keying) over the additive white Gaussian noise channel when a noisy phase reference is derived. Bit-error-rate and cut-off bounds are presented     

Rhodium-catalysed reduction of vanadium pentoxide and tungsten trioxide by hydrogen

Hydrogen reduction of V₂O₅ and WO₃ catalysed by rhodium, both in the pure form and supported on kieselguhr, has been studied. The products obtained at 300°C have been identified as VO₂ and H_xWO₃. In situ electrical resistivity measurements on V₂O₅ pellets, both pure and admixed with the catalyst, show an anomalous resistance increase with temperature, perhaps arising from chemisorption and spillover of hydrogen from rhodium.     

Low-Power Low-Voltage Class-AB Linear OTA for HF Filters with a Large Tuning Range

This letter presents a new low-voltage class-AB differential linear OTA. The proposed transconductor uses a novel scheme based on two cross-coupled class-AB pseudo-differential pairs biased by a Flipped Voltage Follower [1]. The transconductor has been designed using a 0.8 m CMOS technology to operate at 2 V supply voltage with only 260 W of quiescent power consumption. Simulation results show 90 MHz bandwidth with more than two decades of transconductance tuning range.     

Very Low Voltage Rail-to-Rail Programmable-Gain CMOS Amplifier

A novel design technique for operating closed-loop amplifier circuits at very low supply voltages is proposed. It is based on the use of quasi-floating gate transistors, avoiding issues encountered in true floating-gate structures such as the initial floating-gate charge, offset drift with temperature, and the gain-bandwidth product degradation. A programmable-gain differential amplifier is designed and implemented following this method. Measurement results of an experimental prototype fabricated in a 0.5-m CMOS technology validate on silicon the proposed technique.     

Novel Architectures of Class AB CMOS Mirrors with Programmable Gain

Two schemes for power-efficient gain-programmable V-I conversion based on class AB CMOS mirrors are introduced. The proposed topologies also allow for high-speed gain-programmable precision rectification. Experimental results from a test chip prototype in 0.5- m CMOS technology with ±1 V supplies are shown that validate the proposed circuits.     

The failure analyses on ZnO varistors used in high tension devices

The main purpose of this work is to evaluate the failure caused by electrical discharge on commercial ZnO varistor doped with oxide of Bi, Sb, Si, Cr, Co utilized in electric transmission systems. In order to observe the effect of electrical discharge over the microstructure and electrical properties of the varistors, two kinds of pulses were applied: long pulse (2000 ms) and short pulse (8/20 μs). In both cases, a decrease in grain size and increase in micropores and leakage current were observed. The degraded samples present oxygen defficiency mainly in the grain boundary and phase tranformation from the bismuth oxide phase.