Kaunas Technological University

Kaunas, Lithuania

Kaunas Technological University

Kaunas, Lithuania
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Rokicki J.,Vilnius Gediminas Technical University | Matiukas V.,Vilnius Gediminas Technical University | Usinskas A.,Vilnius Gediminas Technical University | Adaskevicius R.,Kaunas Technological University
Opto-electronics Review | Year: 2011

This tutorial paper surveys three methods designed to detect the centre line in curvilinear structures. These are the iterative thinning, Steger's and derivatives' methods. We aim to illustrate the effectivness of the chosen methods for processing laser-trace images and magnetic resonance slices of human head. The essence of each three methods is presented and important parameters are discussed. Experiments have been carried out and results are discussed in the light of the quality of the centre line produced and work time of all three methods. © 2011 Versita Warsaw and Springer-Verlag Wien.

Bogorosh A.,Kharkiv Polytechnic Institute | Visniakov N.,Vilnius Gediminas Technical University | Novickij J.,Vilnius Gediminas Technical University | Bubulis A.,Kaunas Technological University | Roizman V.,Khmelnitskiy National University
Journal of Vibroengineering | Year: 2013

Dislocation avalanches and strain bursts in the boards of radio-engineering equipment were investigated. For that purpose a cascade of navigation devices boards was installed on the vibration stand and experiments were performed in the 0.5-10 Hz vibration range at 0 - +45 °C temperature. Amplitude method was applied to determine the coordinates of localized sources of acoustic emission and research of mechanical stress in local points of material was performed using axial compression tests on tensile machine. The results indicate the initial increase in tension and relative deformation and further their decrement. The acquired experimental data on acoustic emission reflect the formation of microcracks and the instability of mechanical tension, its avalanche and explosive tendency in the material when the micro volumes of material are torn.

Bogorosh A.,Kharkiv Polytechnic Institute | Voronov S.,Kharkiv Polytechnic Institute | Visniakov N.,Vilnius Gediminas Technical University | Scekaturoviene D.,Vilnius Gediminas Technical University | Bubulis A.,Kaunas Technological University
Solid State Phenomena | Year: 2015

Components of navigating devices can be affected by acoustic emission and vibration. Therefore prototype samples and electronic components must be tested in such conditions. Heterostructures, which destructed under the action of external physical factors and kinetics of formations of porous defects in silicon substrates, were analyzed. © (2010) Trans Tech Publications, Switzerland.

Zdunczyk Z.,Polish Academy of Sciences | Gruzauskas R.,Lithuanian Veterinary Academy | Juskiewicz J.,Polish Academy of Sciences | Semaskaite A.,Lithuanian Veterinary Academy | And 5 more authors.
Journal of Applied Poultry Research | Year: 2010

Until the end of 2005, antibiotics were used in Europe in poultry nutrition as growth-promoting agents. The general European Union ban on antibiotic growth promoters, beginning in 2006, has encouraged the search for effective alternatives. Research not only on performance, but also on the physiological responses of birds is still sparse. This experiment was conducted to characterize, in addition to performance indices, the physiological effect of an alkaloid preparation, Sangrovit, obtained from the aerial parts Macleaya cordata, on the gastrointestinal tract (mainly ceca) of broiler chickens. Carcass meat characteristics and the fatty acid profile of breast meat were evaluated as well. One-day-old broiler chicks (Cobb 500) were fed a wheatcorn- soybean meal control diet without (control) or with a 30 mg/kg dose of the alkaloid preparation for 5 wk. The Sangrovit treatment did not significantly improve final BW, FCR, or breast muscle weight when compared with the control treatment. The n-6:n-3 fatty acid ratio in breast meat was significantly increased by the Sangrovit treatment. The sensory evaluation of breast and thigh meat did not reveal any negative influence of dietary supplementation with the alkaloid preparation. Supplementation of 30 mg/kg of the alkaloid-containing preparation Sangrovit in broiler diets without growth promoters can help perpetuate a beneficial cecal environment, reducing the activities of bacterial β-glucosidase (P = 0.095) and β-glucuronidase (P = 0.075) as well as decreasing pH of the digesta (P = 0.060). © 2010 Poultry Science Association, Inc.

Miskinis K.,Kaunas Technological University | Stankevicius V.,Kaunas Technological University | Dikavicius V.,Kaunas Technological University
10th International Conference Modern Building Materials, Structures and Techniques | Year: 2010

The impact sound is the most common kind of structure borne noise in dwellings. To lower the level of impact sound special floor construction - floating floor are used. The main element of floating floors is the resilient interlayer. In this research the dynamic stiffness and compressibility of compound made from recycled styropor (EPS) granules (0.1-6 mm diameter) with hydraulic binder which is used as resilient material was investigated. The dynamic stiffness and compressibility of hardened specimens was measured. The specimen was kept for 72 hours in normal condition. The same specimens for dynamic stiffness and compressibility test were used. The results showed that dynamic stiffness values decrease in average 66 % after compressibility test in comparison with values before the test. © Vilnius Gediminas Technical University, 2010.

Rozenstrauha I.,Riga Technical University | Sosins G.,Riga Technical University | Krage L.,Kaunas Technological University | Sedmale G.,Riga Technical University | Vaiciukyniene D.,Kaunas Technological University
Boletin de la Sociedad Espanola de Ceramica y Vidrio | Year: 2013

Two main by-products or waste from the production of glass fibre are following: sewage sludge containing montmorillonite clay as sorbent material and ca 50 % of organic matter as well as waste glass from aluminiumborosilicate glass fibre with relatively high softening temperature (> 600 °C). In order to elaborate different new ceramic products (porous or dense composites) the mentioned by-products and illitic clay from two different layers of Apriki deposit (Latvia) with illite content in clay fraction up to 80-90 % was used as a matrix. The raw materials were investigated by differential-thermal (DTA) and XRD analysis. Ternary compositions were prepared from mixtures of 15 - 35 wt % of sludge, 20 wt % of waste glass and 45 - 65 wt % of clay and the pressed green bodies were thermally treated in sintering temperature range from 1080 to 1120 °C in different treatment conditions. Materials produced in temperature range 1090 - 1100 °C with the most optimal properties - porosity 38 - 52 %, water absorption 39 - 47 % and bulk density 1.35 - 1.67 g/cm3 were selected for production of porous ceramics and materials showing porosity 0.35 - 1.1 %, water absorption 0.7 - 2.6 % and bulk density 2.1 - 2.3 g/cm3 - for dense ceramic composites. Obtained results indicated that incorporation up to 25 wt % of sewage sludge is beneficial for production of both ceramic products and glass-ceramic composites according to the technological properties. Structural analysis of elaborated composite materials was performed by scanning electron microscopy(SEM). By X-ray diffraction analysis (XRD) the quartz, diopside and anorthite crystalline phases were detected.

Padgurskas J.,Lithuanian University of Agriculture | Zunda A.,Lithuanian University of Agriculture | Andriusis A.,Lithuanian University of Agriculture | Metrikaite D.,Lithuanian University of Agriculture | And 3 more authors.
Journal of Friction and Wear | Year: 2014

The tribological study of the parameters of piezoactuator when switching over contacts a trib- ocouple deals with of rotation of piezoactuator steady during 500 m when the rotor from polished steel C45 (HRC 50, Ra = 2 μm) is used. Often the rotation speed leaps up to 16-18 min-1. The coating with fluoroli- gomeric material stabilizes the rotation and continuous operation of piezoactuator. The steady rotation speed starts from a 50-m run (350 rotor revolutions, i.e., cycles of repeating impacts on the surface). The lower dam- age of the friction surface takes place after a 500-m run when the rotor is coated with fluoroligomeric mate- rial. Scratch tests show that steel surface with the fluoroligomeric layer has a lower hardness and 20% higher elasticity compared to a noncoated surface. © 2014 Allerton Press, Inc.

Guarracino M.R.,National Research Council Italy | Guarracino M.R.,Kaunas Technological University | Irpino A.,The Second University of Naples | Jasinevicius R.,Kaunas Technological University | Verde R.,The Second University of Naples
Information Sciences | Year: 2013

Supervised classification of data affected by noise or error, with unknown probability distribution, is a challenging task. To this extend, we propose the Fuzzy Regularized Eigenvalue Classifier, based on a recent technique to classify data in two or more classes. We compare the execution time and accuracy of the classifier with other de facto standard methods. With the adoption of a novel membership function, the classifier is capable to produce more accurate models that well compare with results obtained by other methods, and fuzzy weighting functions, on benchmark datasets. © 2012 Elsevier Inc. All rights reserved.

Kaminskas G.,Vilnius University | Bartkus E.V.,Kaunas Technological University | Pilinkus D.,Vilnius University
Engineering Economics | Year: 2011

Most of the leadership theories emphasize characteristics of leaders (Kirkpatrick, 1991, Katz, 1995, Stogdill, 1963), followers, context (Blanchard, 1985, Fiedler, 1974) or their combination (House, 1974) and leadership is considered from the point of view what leaders give to their follower by treating them as a group. Theory of leadership evaluating leadership from the point of view of relationship is the theory of leader-member exchange (LMX) (Dansereau, F., Graen, G. B. and Haga, W., 1975). This theory considers the influence of subordinates on the leader to be of the same importance as the influence of leaders on subordinates. LMX theory presents the model of the creation of leadership which proposes leaders to search for the methods of creation of mutual trust and respect with all subordinates, thus changing the whole wok unit into an inside group. LMX theory prompts leaders to create relationship of mature partnership with every subordinate and to avoid any inequity. We raise the hypothesis: the quality of interaction between a leader and a follower and the process of the creation of leadership at the same time are influenced by the age and sex of subordinates, therefore while creating leadership these aspects should be taken into account. The research of the interaction between the leader and followers performed among the higher medical staff of stationary departments of Kaunas county hospital and its branch Kaunas psychiatry hospital showed some differences among sexes in the process of the creation of leadership and some influence of the age of a follower to the quality of interchange with the leader. The analysis of the interaction between a leader and followers allowed us to make the final generalization as follows: 1) the more aged, the more often high quality interchange is formed with a leader and mostly this tendency is exposed among respondents aged 41-60 who already have some work and life experience; 2) despite the fact that the major part of the investigated group consisted of women, even twice more men in comparison to women group create high quality interchange with the leader; 3) men trust their leader more than women and are ready to protect and to explain his/her decision. 4) women feel less understood by their leaders, considerably less than men trust them and more seldom are ready to protect themselves and to explain their decisions; 5) however, despite the quality of interchange with the leader, women who form the major part of the members of the dyad are not less pleased in their relationship with the leader than men. Therefore it could be stated that despite a prompt attempt of leaders (by LMX theory) to create relationship of mature partnership with every subordinate avoiding any inequity, it is necessary that such aspects as age and sex of followers should be taken into account.

Bartkus E.V.,Kaunas Technological University | Grunda R.,Vilnius University
Engineering Economics | Year: 2011

Business sustainability assessment requires data, which can be gathered from various information sources. Annual statements are frequently used as a data source, because they are considered to be one of the most important means of the company to communicate with various stakeholders. The document is signed by the management of the company, ensuring that the information in the statement is accurate, and because the statements are audited by an independent third party. The research was intended to solve the problem of the lack of information about the content of Lithuanian companies' annual statements from the perspective of corporate sustainability assessment. Thus, two studies were executed, first analysing annual statements of 15 companies, the second analysing the remaining annual statements of 23 companies, to build understanding of what information is available for further studies of business sustainability assessment. The studies encompassed 38 Lithuanian companies, listed in the Baltic main and secondary lists in Vilnius market in NASDAQ OMX, which constituted 100% of companies. As the studies were done in the beginning of 2010, annual statements for 2008 were used. The methods of the research were logical literature analysis, computer assisted quantitative content analysis, comparative analysis. The first part of the paper reviews the research of Lithuanian scientists in the field of sustainable development, and more specifically, various business and industry sectors. The literature review also includes various business sustainability evaluation models, focussing on the structure of the models, the quantity of companies analysed and the sources of data, used in the evaluations. In the second parts of the paper, the model of business sustainability evaluation is briefly described to create the basic structure for the research of annual statements of the companies. The third part describes the methodology of the research: what data was analysed, how it was analysed, the structure of the research. In the fourth part of the article, the results of the study are presented, explaining what information was most often found in the annual statements and how frequently it was found. Eventually, the findings are discussed from the perspective of whether the availability of information is satisfactory to execute corporate sustainability assessment. The model for business sustainability assessment, used in this study, is based on the idea, that companies have an impact on the environment. But it is not always possible to state in advance weather an impact is positive or negative, as it depends on a specific company case analysed. Thus, the model is created grouping the company impacts into positive, negative and situational. Positive impacts cover employee training, employing disabled, employing people with no work experience and elderly ones, workplace safety, family friendly workplace, lab or union existence, taxes paid, salaries paid, profit and donations to charity. Negative impacts cover pollution, product end-of-life pollution, discrimination, corruption, resource depletion, wasted materials, child lab or and fines paid to the government. Situational impacts cover product/service itself, and the delivery of this product or service to the society. The study showed, that the information, present in all the 39 annual statements, is the information about profit, paid taxes, paid salaries, and the product or service the company produces. 82% of the annual statements had the information about employee training, 79% had the information about the materials and resources used, 72% of statements had the information about donations to charities, 69% of statements had information about fines paid, and 67% of annual statements had the information about labour unions. Among the information, that was not found at all in the annual statements is child labour and employing inexperienced, with 0% occurrence, 5% (2 annual statements out of 39) had some information about employing the disabled and corruption. The terms "renewable" and "unrenewable" (Lithuanian equivalents) were found mentioned once each, showing, that the information about renewable resources cannot be found in the statements. From the sustainability perspective, this lack of information greatly limits the possibilities to include renewable resources, as one of the indicators, in business sustainability evaluation. The results show, that because of the lack of some information in the annual statements, either the business sustainability assessment model should be simplified and data, that is not available, should be removed or substituted, or other sources of information (such as corporate websites, press releases or interviews) should be employed to gather the data needed for the evaluation of corporate sustainability. The third possibility is executing empirical business sustainability evaluation studies explicitly stating the limitations- what necessary information was not available during the research.

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