SeSFJava harness: service and assertion checking for protocol implementations

Many formal specification languages and associated tools have been developed for network protocols. Ultimately, formal language specifications have to be compiled into a conventional programming language and this involves manual intervention (even with automated tools). This manual work is often error prone because the programmer is not familiar with the formal language. So our goal is to verify and test the ultimate implementation of a network protocol, rather than an abstract representation of it. We present a framework, called services and systems framework (SeSF), in which implementations and services are defined by programs in conventional languages, and mechanically tested against each other. SeSF is a markup language that can be integrated with any conventional language. We integrate SeSF into Java, resulting in what we call SeSFJava. We present a service-and-assertion checking harness for SeSFJava, called SeSFJava harness, in which distributed SeSFJava programs can be executed, and the execution checked against services and any other correctness assertions. The harness can test the final implementation of a concurrent system. We present an application to a data transfer service and sliding window protocol implementation. SeSFJava and the harness has been used in networking courses to specify and test transmission control protocol-like transport protocols and service.     

Retrieval of machining information from feature patterns using artificial neural networks

The integration of design and manufacturing has been the subject of much debate and discussion over a long period of time. Recognition of feature patterns and the retrieval of necessary machining information from those patterns play vital roles in this process of integration, as they facilitate the selection of the necessary manufacturing parameters required to transform the designed product into a final physical entity. Although the problem of recognising features from a solid model has been exclusively studied, most existing product models are expressed as engineering drawings. Moreover, the solid model can only provide complete 3D topological and geometrical data and some of the essential machining information cannot be retrieved. In this paper, an approach for defining engineering features, like slots, steps and circular pockets is proposed using binary strings. Two artificial neural networks, one for slots and steps and the other for circular pockets, are designed and developed. These neural networks take the binary strings as inputs and give the relevant machining information as outputs. The networks are trained with non-interacting features and after training, those will become capable of providing the necessary machining information for both non-interacting and interacting features in the domains of slots, steps and circular pockets. This novel approach can further be extended to other features for retrieving relevant machining information and thus facilitating the effective integration of design and manufacturing.     

Corrosion behaviour of solar reflector coatings on AA 2024T3 - an electrochemical impedance spectroscopy study

Electrochemical impedance spectroscopy in the 100 kHz-5 mHz frequency range was applied to the study of corrosion behaviour of solar reflector coatings on AA 2024 exposed to 3.5% NaCl solution. Solar reflector coatings were obtained by sulphuric acid anodization of the alloy in presence of oxo-anions of molybdenum or vanadium. Corrosion behaviour of the oxide films was evaluated by determining the film resistance and capacitance values with exposure time. Comparison of the results reveals that, vanadium addition confers better barrier properties and corrosion resistance than molybdenum additions. Analysis using damage function based on the impedance at 100 mHz shows that solar reflector coatings have improved corrosion behaviour than normal sulfuric acid anodized oxide films on AA 2024.     

Solving Part-Type Selection and Operation Allocation Problems in an FMS: An Approach Using Constraints-Based Fast Simulated Annealing Algorithm

Production planning of a flexible manufacturing system (FMS) is plagued by two interrelated problems, namely 1) part-type selection and 2) operation allocation on machines. The combination of these problems is termed a machine loading problem, which is treated as a strongly NP-hard problem. In this paper, the machine loading problem has been modeled by taking into account objective functions and several constraints related to the flexibility of machines, availability of machining time, tool slots, etc. Minimization of system unbalance (SU), maximization of system throughput (TH), and the combination of SU and TH are the three objectives of this paper, whereas two main constraints to be satisfied are related to time and tool slots available on machines. Solutions for such problems even for a moderate number of part types and machines are marked by excessive computational complexities and thus entail the application of some random search optimization techniques to resolve the same. In this paper, a new algorithm termed as constraints-based fast simulated annealing (SA) is proposed to address a well-known machine loading problem available in the literature. The proposed algorithm enjoys the merits of simple SA and simple genetic algorithm and is designed to be free from some of their drawbacks. The enticing feature of the algorithm is that it provides more opportunity to escape from the local minimum. The application of the algorithm is tested on standard data sets, and superiority of the same is witnessed. Intensive experimentations were carried out to evaluate the effectiveness of the proposed algorithm, and the efficacy of the same is authenticated by efficiently testing the performance of algorithm over well-known functions     

Acid‐Controlled Chemodivergent Synthesis of Three Differently Substituted Quinolines via Site Selective Coupling of ortho‐ Aminoaryl Ketones with α‐Enolic Dithioesters

A straightforward approach for the chemodivergent synthesis of quinolines is described through site‐selective coupling of ortho‐aminoaryl ketones with α‐enolic dithioesters (DTEs) under solvent‐free conditions. The operationally and user‐simple one‐pot methodology is based on the trifunctional nature of DTEs. Both the carbonyl and the thiocarbonyl moiety in α‐enolic dithioesters were employed for the efficient construction of three differently substituted quinolines in a chemoselective manner simply by variation of an easy to handle acid catalyst.

     

Remote health monitoring system for detecting cardiac disorders

Remote health monitoring system with clinical decision support system as a key component could potentially quicken the response of medical specialists to critical health emergencies experienced by their patients. A monitoring system, specifically designed for cardiac care with electrocardiogram (ECG) signal analysis as the core diagnostic technique, could play a vital role in early detection of a wide range of cardiac ailments, from a simple arrhythmia to life threatening conditions such as myocardial infarction. The system that the authors have developed consists of three major components, namely, (a) mobile gateway, deployed on patient''s mobile device, that receives 12‐lead ECG signals from any ECG sensor, (b) remote server component that hosts algorithms for accurate annotation and analysis of the ECG signal and (c) point of care device of the doctor to receive a diagnostic report from the server based on the analysis of ECG signals. In the present study, their focus has been toward developing a system capable of detecting critical cardiac events well in advance using an advanced remote monitoring system. A system of this kind is expected to have applications ranging from tracking wellness/fitness to detection of symptoms leading to fatal cardiac events.Inspec keywords: cardiovascular system, diseases, patient monitoring, electrocardiography, medical signal processing, medical signal detection, electric sensing devices, medical disordersOther keywords: remote health monitoring system, cardiac disorder detection, clinical decision support system, cardiac care, electrocardiogram signal analysis, core diagnostic technique, cardiac ailments, arrhythmia, myocardial infarction, life threatening conditions, mobile gateway, patient mobile device, ECG signals, ECG sensor, remote server component, point‐of‐care device, fatal cardiac events     

Sensitivity of Thermophysical Material Properties on Solidification Simulation of Al-Si Binary Alloys

The challenges in the numerical simulation of the solidification of binary alloys are not only in the complexity of the algorithms themselves, but also in the validity of the data used to define the material properties of the various phases to obtain a valid simulation. The effect of material properties on the numerical simulations was investigated in the present study wherein the Al-3 wt pct Si hypoeutectic binary alloy was solidified such that the solidification front traveled against the gravity vector (upward solidification). Numerical simulations were carried out with a new algorithm that was developed to include the effect of undercooling of the liquid temperature prior to the solidification event. The effect of specific heat of solid, density of solid, solute diffusivity coefficient of liquid, and thermal conductivity of solid on transient temperature distribution and solidification start time at mushy zone/liquid interface was investigated. It was found that specific heat and thermal conductivity of the solid could not be assumed as constants, whereas most properties in the liquid phase could be assumed as constants for the temperature range used in the study and the experiments used for validation (low initial melt superheat temperature). These properties were enumerated and quantified. The results of the numerical simulations using the optimum set of material properties were validated by experiments.