Evaluation of Energy Saving Operational Modes for Industrial Fracture Connected Processes on the Basis of Incubation Time Fracture Criterion

A problem for a central crack in a plate subjected to plane strain conditions is investi-gated. Mode Ⅰ crack loading is created by a dynamic pressure pulse applied at a large distance from the crack. It was found that for a certain combination of amplitude and duration of the pulse applied, the energy transmitted to the sample has a strongly marked minimum, meaning that with the pulse amplitude or duration moving away from the optimal values, minimum energy required for initiation of crack growth increases rapidly. The results obtained indicate a possibility to optimise energy consumption of different industrial processes connected with fracture. Much could be gained in, for example, drilling or rock pounding where energy input accounts for the largest part of the process cost. Presumably further investigation of the effect observed can make it possible to predict optimal energy saving parameters, i.e. frequency and amplitude of impacts, for industrial devices, e.g. bores, grinding machines, and hence significantly reduce the process cost. The pre-diction can be given based on the parameters of the media fractured (material parameters, preva-lent crack length and orientation, etc.).     

Abnormalities of masseter inhibitory reflex in patients with episodic tension-type headache

Objective: To investigate the masseter inhibitory reflex (MIR) and its eventual changes in patients with episodic tension-type headache (TTH). Methods: MIR was studied in 21 patients with episodic TTH and 30 healthy subjects, with age and sex matched to the study cohort. Median age of patients was 17,0 years (ranged 16～49 years), median duration of disease 12 months (1～5 years), and median frequency of headache 7.5 d per month. Results: The second period of suppression (S2) of MIR was reduced in intensity and duration in 10% of controls and 66.7% (confidence interval (CI)=45.3%～85%; P<0.05) of patients with episodic TTH (χ2=74.9; P<0.001). In 3 (14.3%) of patients with episodic TTH, S2 was completely absent. No significant correlation between the duration of disease and headache frequency was found. Conclusion: Our results confirm the link between episodic TTH and reduction or absence of S2. Teenage patients with episodic TTH may exhibit marked pathological changes in S2 in contrast to older individuals.     

Quantitative measures for assessment of the hydraulic excavator digging efficiency

In this paper, quantitative measures for the assessment of the hydraulic excavator digging efficiency are proposed and developed. The following factors are considered: (a) boundary digging forces allowed for by the stability of an excavator, (b) boundary digging forces enabled by the driving mechanisms of the excavator, (c) factors taking into consideration the digging position in the working range of an excavator, and (d) sign and direction of potential digging resistive force. A corrected digging force is defined and a mathematical model of kinematic chain and drive mechanisms of a five-member excavator configuration was developed comprising: an undercarriage, a rotational platform and an attachment with boom, stick, and bucket. On the basis of the mathematical model of the excavator, software was developed for computation and detailed analysis of the digging forces in the entire workspace of the excavator. By using the developed software, the analysis of boundary digging forces is conducted and the corrected digging force is determined for two models of hydraulic excavators of the same mass (around 17 000 kg) with identical kinematic chain parameters but with different parameters of manipulator driving mechanisms. The results of the analysis show that the proposed set of quantitative measures can be used for assessment of the digging efficiency of existing excavator models and to serve as an optimization criterion in the synthesis of manipulator driving mechanisms of new excavator models.     

The Academic Spin-Offs as an Engine of Economic Transition in Eastern Europe. A Path-Dependent Approach

The paper questions some of the premises in studying academic spin-offs in developed countries, claiming that when taken as characteristics of ‘academic spin-offs per se,’ they are of little help in understanding the phenomenon in the Eastern European countries during the transitional and post-transitional periods after 1989. It argues for the necessity of adopting a path-dependent approach, which takes into consideration the institutional and organisational specificities of local economies and research systems and their evolution, which strongly influence the patterns of spin-off activity. The paper provides new findings and original arguments in support of Balazs’ seminal theses (Balazs 1995, 1996) about the emergence of academic spin-offs during the early transition. It reveals key economic and policy mechanisms bearing on academic entrepreneurship in Eastern Europe, such as the tensions between economic and political nomenclatures of former Communist Parties, where the dismantling or preservation of the power of political nomenclature resulted in different patterns of development—rapid reforms in the ‘first wave’ of EU accession countries or the establishment of rent-seeking and assets-stripping economies in countries like Bulgaria and Romania, making the transition period especially difficult. In the latter, a specific economic environment emerged, unknown in Western Europe and in the ‘champions’ of transition—such as suppression of the authentic entrepreneurship in a number of economic sectors, disintegration of corporate structures, etc. Thus, the paper reveals the common ground behind the two conflicting tendencies in post-socialist academic spin-offs, partially outlined in other research (Simeonova 1995; Pavlova 2000): as an authentic form of academic entrepreneurship grasping the opportunities opened up by the economic crisis and compensating failures in science and technology policy on the one hand, and as specific rent-seeking strategy draining valuable public assets on the other (the latter, in turn, boosting the negative attitudes in local scientific communities). The paper provides new findings about the evolution of the academic spin-offs in Bulgaria along the two polar trends and their positive and negative repercussions on parent research institutions. The results were achieved in the PROKNOW Project, EC 6th Framework Program.     

Confidence and reliability measures in speaker verification

Speaker verification is a biometric identity verification technique whose performance can be severely degraded by the presence of noise. Using a coherent notation, we reformulate and review several methods which have been proposed to quantify the uncertainty in verification results, some with a view to coping with the effects of mismatched training-testing environments. We also include a recently proposed method, which is firmly rooted in a probabilistic approach and interpretation, and explicitly measures signal quality before assigning a reliability value to the speaker verification classifier's decision. We evaluate the performance of the confidence and reliability measures over a noisy 251-users database, showing that taking into account signal-domain quality can lead to better accuracy in prediction of classifier errors. We discuss possible strategies for using the measures in a speaker verification system, balancing acquisition duration and verification error rate.     

Promotion of Reading and Early Literacy Skills in Schools: a comparison of three European countries

This article gives a short overview based on the EU High Level Group of Experts on Literacy (HLWG) report to address issues and challenges in Europe on improving literacy competencies in schools. Furthermore, an analysis is conducted focusing on the promotion of reading and early literacy skills in schools taking into account psychological and institutional learning conditions in three countries (Denmark, Germany, and France) with different outcomes in PIRLS 2011 (Progress in International Reading Literacy Study). Country comparison is conducted using multiple groups – multilevel structural equation modelling (MG-MSEM). An important finding is that policy action taken in order to evaluate and improve school effectiveness in each country must address particular needs of its educational system. Suggestions for improving reading achievement in schools are derived from the analysis.     

Tensions in Higher Education Leadership: Towards a Multi‐Level Model of Leadership Practice

UK higher education is undergoing a period of significant change that generates a series of tensions and difficulties for universities and university leaders. This paper explores these tensions through analysis of findings from a study comprising 152 semi‐structured face‐to‐face interviews in 12 UK universities. Building on from theories of ‘distributed leadership’ in schools, five main constituent elements of leadership practice in higher education are identified (personal, social, structural, contextual and developmental) and explored to show how they shape perceptions and experiences of leadership. The paper concludes with a refined model that teases apart the multilayered nature of higher education leadership at individual, group and organisational levels. In particular, it is argued that ‘social capital’ and ‘social identity’ act as important bridges between individual agency and organisational structure and that although widely distributed, higher education leadership may be best regarded as ‘hybrid’.     

Formation of the information infrastructure for the innovative integration of the states- participants in the CIS

This paper outlines the activities of the Interstate Coordination Council for Scientific and Technical Information (ICCSTI), which is aimed at coordination of the actions of states-participants of the CIS in the exchange of scientific and technical information, for the informational support of interstate scientific and technical cooperation. It examines the strategy and structure of information support of innovation processes as part of the innovative integration of the CIS, which is implemented together with the formation of an integrated information environment, as well as shaping the information infrastructure of the innovative integration of states-participants of the CIS based on the concept of scientific information to ensure programs and projects of states-participants of CIS in the sphere of innovations. We describe a distributed multilevel system of information support of innovation, which is designed for the integrated management of information resource sharing.     

Evaluation of Energy Saving Operational Modes for Industrial Fracture Connected Processes on the Basis of Incubation Time Fracture Criterion

A problem for a central crack in a plate subjected to plane strain conditions is investigated.Mode Ⅰ crack loading is created by a dynamic pressure pulse applied at a large distance from the crack.It was found that for a certain combination of amplitude and duration of the pulse applied,the energy transmitted to the sample has a strongly marked minimum,meaning that with the pulse amplitude or duration moving away from the optimal values,minimum energy required for initiation of crack growth increases rapidly.The results obtained indicate a possibility to optimise energy consumption of different industrial processes connected with fracture.Much could be gained in,for example,drilling or rock pounding where energy input accounts for the largest part of the process cost.Presumably further investigation of the effect observed can make it possible to predict optimal energy saving parameters,i.e.frequency and amplitude of impacts,for industrial devices,e.g.bores,grinding machines,and hence significantly reduce the process cost.The prediction can be given based on the parameters of the media fractured (material parameters,prevalent crack length and orientation,etc.).