Evaluation of amperometric glucose biosensors based on glucose oxidase encapsulated within enzymatically synthesized polyaniline and polypyrrole

In this article potential and suitability of enzymatically synthesized conducting polymers polyaniline (PANI) and polypyrrole (PPY) for fabrication of enzymatic amperometric glucose biosensors were evaluated. The polymerisation of these polymers was induced by catalytic activity of glucose oxidase (GOx) from Penicillium vitale cross-linked by glutaraldehyde (GA) on the graphite rod electrode (GOx-electrode) surface. The main precursors for initiation of polymerisation reactions were hydrogen peroxide as an initiator of polymerisation reaction and β-d-gluconic acid as a medium, which reduced the pH towards acidic one is the most suitable for the formation of PANI and PPY. During the polymerisation reactions the immobilized GOx was self-encapsulated within formed PANI or PPY layers in order to form GOx/PANI- and GOx/PPY-modified electrodes (GOx/PANI-electrode and GOx/PPY-electrode, respectively). Kinetic properties of GOx, which is acting as a biocatalyst in GOx/PANI- and GOx/PPY-electrodes, were studied and results were compared with GOx-electrode. The results show that in both GOx/PANI- and GOx/PPY-electrodes self-encapsulated GOx exhibited different parameters of catalysed reaction kinetics due to increasing diffusion limitations if compared with that of the GOx-electrode and it allowed the detection of glucose in a wider concentration interval. Moreover, both GOx/PANI- and GOx/PPY-electrodes exhibited good operational stability and reproducibility of analytical signal. The electrochemical characteristics of formed PANI and PPY in the GOx/PANI- and GOx/PPY-electrodes were also determined. In addition, the influence of temperature, pH and common interfering compounds on the steady-state current response of modified electrodes were investigated and discussed.     

Efficient Euclidean projections via Piecewise Root Finding and its application in gradient projection

Recently, the gradient (subgradient) projection method, especially by incorporating the idea of Nesterov's method, has aroused more and more attention and achieved great successes on constrained optimization problems arising in the field of machine learning, data mining and signal processing. In the gradient projection method, a critical step is how to efficiently project a vector onto a constraint set. In this paper, we propose a unified method called Piecewise Root Finding (PRF) to efficiently calculate Euclidean projections onto three typical constraint sets: ?₁-ball, Elastic Net (EN) and the Intersection of a Hyperplane and a Halfspace (IHH). In our PRF method, we first formulate a Euclidean projection problem as a root finding problem. Then, a Piecewise Root Finding algorithm is applied to find the root and global convergence is guaranteed. Finally, the Euclidean projection result is obtained as a function of the found root in a closed form. Moreover, the sparsity of the projected vector is considered, leading to reduced computational cost for projection onto the ?₁-ball and EN. Empirical studies demonstrate that our PRF algorithm is efficient by comparing it with several state of the art algorithms for Euclidean projections onto the three typical constraint sets mentioned above. Besides, we apply our efficient Euclidean projection algorithm (PRF) to the Gradient Projection with Nesterov's Method (GPNM), which efficiently solves the popular logistic regression problem with the ?₁-ball/EN/IHH constraint. Experimental results on real-world data sets indicate that GPNM has a fast convergence speed.     

Acousto-capacitive tomography of liquid multiphase systems

This paper discusses a tomographic approach focusing on ultrasonic measurements to monitor liquid multiphase mixtures. Separately a capacitive tomography low-cost setup is regarded. Both sensor arrays aim for the localization of variable phase boundaries and the physical characterisation of spatially distributed phases. Focusing on a real time processing, a reduced number of transducers in combination with a fast linear modelling and direct image reconstruction methods are used. Experimental results of a layered 3-phase-system validate the potential and limits of physical resolution of both approaches. Finally, the prospectively intended data fusion of both approaches is discussed.     

Selection of strategies in judgment-based effort estimation

We currently know little about the factors that motivate the selection and change of strategy in judgment-based effort estimation. A better understanding of these issues may lead to more accurate judgment-based effort estimates and motivates the four experiments reported in this paper. The experiments’ two main results are the identification of the importance of “estimation surprises” (large estimation errors) to motivate estimation strategy change and the large individual variation in the initial choice of estimation strategy. The individual variation seems not only to be a result of differences in previous experiences, but also a result of differences in the mental “accessibility” of the strategies. We found, for example, that the use of a type of strategy was increased when we instructed a developer to use the same type of strategy on unrelated tasks immediately before.     

Towards new web services based supervisory systems in complex industrial organizations: Basic principles and case study

Mobility, cooperation and the information access of the different human actors within a complex industrial organization are some of the concerns of web-based HMI design. In this paper we highlight the application of some key concepts of web services for the specification and design of a complex supervisory web-based HMI. Hence, a novel approach based on a service oriented architecture and web services allowing flexible and transparent interaction between the field devices and human operators currently being considered is now possible. An overall design framework is presented and discussed. A real representative case study illustrating this approach is described and discussed from the human-machine interaction point of view, as well as further work.     

A semantic approach to a framework for business domain software systems

In enterprise firms, enormous amounts of electronic documents are generated by business analysts and other business domain application users. Applications that use these documents are often driven by business logic that is hard-coded together with application logic. One approach to the separation of business logic from applications is to create and maintain business and information extraction rules in an external, user-friendly format. The drawback of such an externalization is that the business rules, usually, do not have machine interpretable semantics. This situation often leads to misinterpretation of domain analysis documents, which can inhibit the productivity of computer-assisted analytical work and the effectiveness of business solutions. This paper proposes an ontology and rule-based framework for the development of business domain applications, which includes semantic processing of externalized business rules and to some extent externalization of application logic. The creation of external information extraction rules by the business analyst is a cumbersome and time consuming task. In order to overcome this problem, the framework also includes a rule learning system to semi-automate the generation of information extraction rules from source documents with the help of manual annotations. The main idea behind the work presented in this paper is to re-engineer very large enterprise information systems to adapt to Semantic Web computing techniques. The work presented in this paper is inspired by an industrial project.     

The role of the customer order decoupling point in production and supply chain management

In order to compete successfully, operations in any type of firm need to be strategically aligned to the market requirements. This concerns both manufacturing and supply chain operations. The customer order decoupling point (CODP) is getting increasing attention as an important input to the design of manufacturing operations as well as supply chains. This paper investigates the impact of the position and role of the CODP on issues of concern for production and supply chain management. The focus is on the design and strategic planning aspects of the supply chain, and the design of manufacturing planning and control systems. The paper proposes a dual design approach for production and supply chain planning systems; one type of system for operations upstream the CODP and another type of system for downstream operations in order to fully support the characteristics and objectives of each respective part of the supply chain.