63 research outputs found

    Increasing a large petrochemical company efficiency by improvement of decision making process

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    The paper shows the results of a research conducted in a large petrochemical company, in a state under transition, with the aim to "shed light" on the decision making process from the aspect of personal characteristics of the employees, in order to use the results to improve decision making process and increase company efficiency. The research was conducted by a survey, i.e. by filling out a questionnaire specially made for this purpose, under real conditions, during working hours. The sample of the respondents is representative for the goal of the research and consists of 82 employees, of all levels of decision making, education, age structure, and years of service. The data was processed by appropriate mathematical-statistical techniques: factor analysis, cluster analysis, correlation. For determining the important factors in decision making process, a type of factor analysis was used - the principal components analysis and the normalized Varimax rotation procedure. The basic hypotheses of research, related to the readiness of the employees for independent decision making, readiness for risk taking, determining the level of usage of intuition, organization atmosphere, general and personal characteristics of employees, have been proven. The results of the research indicate that the decision making process is a complex one in the organization and that there is a tendency of the employees towards collective decision making, as it used to be done. A significant result is that the employees at the managing positions are more ready for independent decision making than the employees at the executive positions. Based on the results of the research, it is possible to draft managerial and organizational measures for increasing the level of readiness for independent and individual decision making, as well as increase company efficiency

    State-space realization of a describing function

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    The describing function is a powerful tool for characterizing nonlinear dynamical systems in the frequency domain. In some cases, it is the only available description of a nonlinear operator characterizing a certain subcomponent of the system. This paper presents a methodology to provide a state-space realization of one given describing function, in order to allow the study of the system in the time domain as well. The realization is based on Hammerstein models and Fourier–Bessel series. It can be embedded in time domain simulations of complex configurations with many nonlinear elements interacting, accurately describing the nonlinear saturation of the system. The technique is applied to an example application in the field of combustion instability, featuring self-excited thermoacoustic oscillations. We benchmark the performance of the tool comparing the results with a frequency domain analysis of the same system, obtaining good agreement between the two formulations.This work was supported by the European Research Council through project ALORS N.259620 and by the German Research Association for Combustion Engines (Forschungsvereinigung Verbrennungskraftmaschinen e.V. FVV).This is the accepted manuscript of a paper published in Nonlinear Dynamics (Ghirardo G, Ćosić B, Juniper MP, Moeck JP, Nonlinear Dynamics, 2015, doi:10.1007/s11071-015-2134-x). The final version is available at http://dx.doi.org/10.1007/s11071-015-2134-

    A model for the pavement temperature prediction at specified depth

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    This paper examines the existing models for predicting pavement temperatures at a certain depth and formulates a new one using the regression equation to predict the minimum and maximum pavement temperatures at the specified depth depending on the surface pavement temperature and its depth

    Measurement properties of oral health assessments for non-dental healthcare professionals in older people:a systematic review

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    Background: Regular inspection of the oral cavity is required for prevention, early diagnosis and risk reduction of oral-and general health-related problems. Assessments to inspect the oral cavity have been designed for non-dental healthcare professionals, like nurses. The purpose of this systematic review was to evaluate the content and the measurement properties of oral health assessments for use by non-dental healthcare professionals in assessing older peoples' oral health, in order to provide recommendations for practice, policy, and research. Methods: A systematic search in PubMed, EMBASE.com, and Cinahl (via Ebsco) has been performed. Search terms referring to 'oral health assessments', 'non-dental healthcare professionals' and 'older people (60+)' were used. Two reviewers individually performed title/abstract, and full-text screening for eligibility. The included studies have investigated at least one measurement property (validity/reliability) and were evaluated on their methodological quality using "The Consensus-based Standards for the selection of health Measurement Instruments"(COSMIN) checklist. The measurement properties were then scored using quality criteria (positive/negative/indeterminate). Results: Out of 879 hits, 18 studies were included in this review. Five studies showed good methodological quality on at least one measurement property and 14 studies showed poor methodological quality on some of their measurement properties. None of the studies assessed all measurement properties of the COSMIN. In total eight oral health assessments were found: the Revised Oral Assessment Guide (ROAG); the Minimum Data Set (MDS), with oral health component; the Oral Health Assessment Tool (OHAT); The Holistic Reliable Oral Assessment Tool (THROAT); Dental Hygiene Registration (DHR); Mucosal Plaque Score (MPS); The Brief Oral Health Screening Examination (BOHSE) and the Oral Assessment Sheet (OAS). Most frequently assessed items were: lips, mucosa membrane, tongue, gums, teeth, denture, saliva, and oral hygiene. Conclusion: Taken into account the scarce evidence of the proposed assessments, the OHAT and ROAG are most complete in their included oral health items and are of best methodological quality in combination with positive quality criteria on their measurement properties. Non-dental healthcare professionals, policymakers and researchers should be aware of the methodological limitations of the available oral health assessments and realize that the quality of the measurement properties remains uncertain

    Cluster analysis of higher-education competitiveness in selected European countries

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    The subject of research in this paper is higher-education competitiveness on account of its impact on the enhancement of social and economic competitiveness, as well as on the growth of human capital and creation of social knowledge. The purpose of this paper is to group the selected European countries according to higher-education competitiveness, by means of the hierarchical cluster analysis method, with a special focus on the position of Serbia. Higher-education competitiveness in the chosen countries is analysed by means of three indicators of competitiveness: the ratio of the number of students per number of inhabitants, the number of students per number of employed, as well as the amount of budgetary funds allocated per student. The research results indicate different higher-education competitiveness in the analysed countries and also the fact that, according to this analysis, Serbia is in the group of countries with low competitiveness of higher education

    Kontaminacija zrna pšenice, kukuruza, soje i graška vrstama Fusariuma u Hrvatskoj

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    From 2002 to 2008, 203 samples of wheat, maize, soybean, and pea were analysed for the presence of Fusarium species. Contamination with Fusarium spp., expressed as the percentage of seeds with Fusarium colonies, ranged from 5 % to 69 % for wheat, from 25 % to 100 % for maize, from 4 % to 17 % for soybean, and from 3 % to 17 % for pea. 187 isolates were collected and the following 19 species determined: F. graminearum, F. poae, F. avenaceum, F. verticillioides, F. sporotrichioides, F. heterosporum, F. crookwellense, F. tricinctum, F. semitectum, F. oxysporum, F. proliferatum, F. solani, F. equiseti, F. pseudograminearum, F. chlamydosporum, F. sambucinum, F. compactum, F. scirpi, and F. culmorum. Dominant species were F. graminearum on wheat (27 % of isolates), F. verticillioides on maize (83 % of isolates), F. sporotrichioides on soybean (34 % of isolates), and F. proliferatum on pea (29 % of isolates). Among species identifi ed, F. heterosporum, F. crookwellense, F. pseudograminearum, F. sambucinum, and F. compactum have been reported for the fi rst time in Croatia.U periodu od 2002. do 2008. g. analizirana je prisutnost vrsta Fusariuma na 208 uzoraka zrna pšenice, kukuruza, soje i graška. Kontaminacija vrstama Fusariuma, izražena kao postotak sjemenki s kolonijama Fusarium spp., kretala se od 5 % do 69 % na pšenici, od 25 % do 100 % na kukuruzu, od 4 % do 17 % na soji te od 3 % do 17 % na grašku. Prosječna kontaminacija vrstama Fusariuma u različitim godinama varirala je od 10 % do 46 % na pšenici, od 50 % do 91 % na kukuruzu, od 5 % do 9 % na soji te od 7 % do 10 % na grašku. Vrste Fusariuma koje se javljaju na zrnu izolirane su i determinirane s odabranih uzoraka pšenice, kukuruza, soje i graška. Skupljeno je 187 izolata, a utvrđeno je 19 vrsta: F. graminearum, F. poae, F. avenaceum, F. verticillioides, F. sporotrichioides, F. heterosporum, F. crookwellense, F. tricinctum, F. semitectum, F. oxysporum, F. proliferatum, F. solani, F. equiseti, F. pseudograminearum, F. chlamydosporum, F. sambucinum, F. compactum, F. scirpi i F. culmorum. Dominantne vrste bile su F. graminearum na pšenici (27 % izolata), F. verticillioides na kukuruzu (83 % izolata), F. sporotrichioides na soji (34 % izolata) te F. proliferatum na grašku (29 % izolata). U Hrvatskoj su prvi put utvrđene vrste F. heterosporum, F. crookwellense, F. pseudograminearum, F. sambucinum i F. compactum

    Physiological and cell ultrastructure disturbances in wheat seedlings generated by Chenopodium murale hairy root exudate.

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    Chenopodium murale L. is an invasive weed species significantly interfering with wheat crop. However, the complete nature of its allelopathic influence on crops is not yet fully understood. In the present study, the focus is made on establishing the relation between plant morphophysiological changes and oxidative stress, induced by allelopathic extract. Phytotoxic medium of C. murale hairy root clone R5 reduced the germination rate (24% less than control value) of wheat cv. Nataša seeds, as well as seedling growth, diminishing shoot and root length significantly, decreased total chlorophyll content, and induced abnormal root gravitropism. The R5 treatment caused cellular structural abnormalities, reflecting on the root and leaf cell shape and organization. These abnormalities mostly included the increased number of mitochondria and reorganization of the vacuolar compartment, changes in nucleus shape, and chloroplast organization and distribution. The most significant structural changes were observed in cell wall in the form of amoeboid protrusions and folds leading to its irregular shape. These structural alterations were accompanied by an oxidative stress in tissues of treated wheat seedlings, reflected as increased level of H2O2 and other ROS molecules, an increase of radical scavenging capacity and total phenolic content. Accordingly, the retardation of wheat seedling growth by C. murale allelochemicals may represent a consequence of complex activity involving both cell structure alteration and physiological processes.This is a post-peer-review, pre-copyedit version of an article published in Protoplasma. The final authenticated version is available online at: [http://dx.doi.org/10.1007/s00709-018-1250-0
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