Dendrimerai yra susintetinti tik maždaug prieš 20 metų. Pirmą kartą šis terminas buvo paminėtas D. A. Tomalios, pirmame straipsnyje apie dendrimerus. Tačiau dendritinės struktūros pavyzdžių mes esame matę kiekvienas. Tai galbūt viena iš labiausiai paplitusių topologijų mūsų planetoje. Daugybė pavyzdžių tokių struktūrų randama ir gyvoje, ir negyvoje gamtoje. Tai ir žaibo struktūra, sniego kristalas, išėdimo (rudžių) frakcija, taip pat medžių šakos ir šaknys, gyvų organizmų kraujagyslių ir nervų sistemos – visa tai dendritinės struktūros (1. Pav.) [15]. Tačiau gamta sukūrė mūsų Visatos materijos sudėtį per 10 – 13 bilijonų metų. Tuo tarpu žmonija molekules pradėjo sintetinti tik prieš 200 metų. Būtent todėl dabartinės galimybės sukurti ir kontroliuoti molekulės sudėtį ir dydį yra lyginamos su tuo, ką demonstruoja gamta. / This work researches two different families of the Liquid Crystal Dendrimers structural and optical features. Different Dendrimers are: G1, G2, G3, G4, G5 generations, with different external chain number: n = 4, 8, 16, 32, 64 which are connected to the peripheral part of the Dendrimer molecule. The measurements are made in three different ways: • Dendrimers dissolved in chloroform • Dendrimers being as a liquid crystal substance • Microscope photo examples The results of the research determines that in the different generation dendrimers’ absorption spectrum the first maximum fits the dendrimer molecule core absorption, the second – the internal part, the third – the absorption of the peripheral part. The results of the research as well determine that the maximum absorption of the internal part of the dendrimer molecule depends on the number of the external chain. This dependence let as come to conclusion that increasing the number of the external chain, the spectrum of absorption of the internal part of the dendrimer‘s molecule displaces to the long wave range. The forthcoming displace of the second family is bigger comparing to the first one. This let as come to the conclusion that the second family is more relevant to use the dendrimer as the substance to catch and/or transport the nano particles or molecules.

Face detection in video sequence is becoming popular in surveillance applications. The trade-off between obtaining discriminative features to achieve accurate detection versus computational overhead of extracting these features, which affects the classification speed, is a persistent problem. Two ideas are introduced to increase the features’ discriminative power. These ideas are used to implement two frontal face detectors examined on a 2D low-resolution surveillance sequence. First contribution is the parallel classifier. High discriminative power features are achieved by fusing the decision from two different features trained classifiers where each type of the features targets different image structure. Accurate and fast to train classifier is achieved. Co-occurrence of Local Binary Patterns (CoLBP) features is proposed, the pixels of the image are targeted. CoLBP features find the joint probability of multiple LBP features. These features have computationally efficient feature extraction and provide high discriminative features; hence, accurate detection is achieved.

The subject of master thesis „The peculiarities of different physical activity, teenagers’ oriental values, personal features and self–esteem”. Problem question: Do adolescent students, who both sport actively and don’t are different in their value orientation, personal features and self–esteem? To measure different value orientations of different physical activity of adolescent students, B. Boss’s (1967) research method was used; to evaluate personal features R. Cattell (1970) research method was used; to evaluate self–esteem Rosenberg (1965) method was used. The adolescent students were grouped into two groups by purpose: 1. teenagers who take active sports (attend gyms, training every day). 2. teenagers who are physically passive (attending just physical training lessons). Two hundred students participated in the research, which had different training activities: 100 students, taking active sports, 100 students – physically passive, among which 100 boys and 100 girls. The hypothesis of the research: 1. Teenagers, who sport actively, are apt to communicate and cooperate less with others (Bredemeir, 1994). 2. Students, who sport actively, have these personal features: feeling of loneliness, reticence (Zagainov, 1984), anxiety, sensitivity (Miškinis, 2002). 3. Teenagers, who sport actively, have higher level of self–esteem, they rely upon themselves more than those who actively passive (Stambulova, 1999; Šukys, 2000; Palujanskienė, 2003). The data of the... [to full text]

Paskutiniais dešimtmečiais puslaidininkių fizika vaidino svarbų vaidmenį beveik kiekvienoje šiuolaikinių technologijų srityje. Šiame greitai besikeičiančiame pasaulyje mūsų jau nebetenkina supantys buities ir darbo prietaisai, valdomi naudojantis elektronais. Mums reikalingas didesnis kompiuterių operatyvumas, didesnė atminties talpa, greitesnis telekomunikacinis ryšys, ir todėl reikalingos naujos technologijos bei sprendimai. Naujas žingsnis fotoninės struktūros. Žinių ir technologijų pasiekimai leidžia fotoninių sturktūrų savybes taikyti šviesos valdymui. Dabartiniame optinės fizikos tyrinėjimų etape šviesos sąveika su medžiaga labai aktuali: ji gali atrodyti universali ir invariantiška, kadangi šviesa jau kontroliuojama pasitelkus hibridinius fotoninius kristalus. Šių darinių tyrimai patrauklūs tiek fundamentaliam, tiek taikomajam mokslui. Į opalą infiltravę skystąjį kristalą, gauname hibridinį fotoninį kristalą. Jo optines savybes galima keisti priklausomai nuo infiltruotos medžiagos lūžio rodiklio. Fotoniniai kristalai, reikia tikėtis, bus taikomi ateities fotoniniuose įrenginiuose, telekomunikacijoje. Su šia sritimi siejamos tokios pat ar net didesnės viltys, kokios buvo siejamos su prieš 50 metų išrastu puslaidininkiniu tranzistoriumi, pakeitusiu techniką ir davusiu impulsą naujoms mokslo kryptims. Teoriškai fotoninių kristalų egzistavimą nepriklausomai vienas nuo kito 1987 metais pirmieji aprašė E.Jablonovičius ir S. Johnas. Tačiau prireikė dar dešimt metų, kol buvo... [toliau žr. visą tekstą] / We live in the rapidly developing technological world. However, fields of communication, computer memory, and data processing require considerable improvements. The speed of data transportation is acceptable but capacity is low. There is a growing need for new technologies that rapidly detect and treat diseases at an early stage or even pre-stage. When we get accustomed to the advance, we demand more compact, energy-efficient, rapidly-responding and environmentally-safe technologies. During the last century this problem was solved by switching to transportation of electronic data, which connected people around the world. This approach had changed our lives, but about twenty years ago this technology reached its limits, while need for an even higher transportation capacity increases. Now we need faster computers and other state-of-the-art technological solutions: electrons are too slow and we have to use photons. Over the last decade, the steady progress regarding ability to fabricate hybrid photonic nanostructures led to a rich variety of different one-, two-, and three-dimensional dielectric/organic and/or metallic periodic structures. They demonstrate qualitatively new and fascinating linear-optical, nonlinear-optical, and quantum-optical features which provide an unprecedented control of light propagation and light-matter interaction. Photonic-based technology, coupled with nanotechnology, can meet many of these challenges. In this work fabrication of hybrid photonic... [to full text]

The purpose of the research- to investigate the influence of the physical education benefit’s understanding for the physical features’ change of both sexes 11th class schoolchildren in secondary school. Seventy nine schoolgirls and schoolboys, whose belong to the main medical physical ability group and attend Kalvarija secondary school, took part in our pedagogical experiment. The experiment was organized during the school year of 2004-2005. In September 2004 schoolchildren were distributed into two experimental (E1 group of 19 schoolgirls and 21 schoolboys) and two control (E2 group of 20 schoolgirls and 19 schoolboys) classes. “The experimental program of knowledge education” was applied for group E1, group E2 had the same physical education lessons as earlier. Research methods used in a Masters thesis were as follows: analysis of literature, questionnaire method, physical features’ testing, statistical analysis. After the questioning of schoolchildren it became clear, that physical education��s knowledge and it’s influence for the change of schoolgirls’ and schoolboys’ physical features, also factors making impact for approach to have sport are very important. EUROFIT and other physical tests were used to identify physical features of pupils. The results of questioning the schoolchildren shown, that only about half of them think, that physical education lessons are meaningful. It’s reasons could be the lack of physical education knowledge and the absence of textbook of... [to full text]

Magistro darbo tikslas yra tarpusavyje palyginti klasifikavimui skirtų požymių mažinimo metodus, kurie turimą požymių aibę transformuoja į mažesnės eilės aibę. Duomenų klasifikavimo kokybė transformuotoje požymių erdvėje turi nenukentėti. Eksperimentams naudotos keturios realių duomenų bazės. Kiekvienai duomenų bazei tikrinama hipotezė apie vidutinių reikšmių lygybę, t.y. lyginamos dvi skirtingos vidutinės klasifikavimo klaidos ir nuspręsta ar jos yra panašios, ar skirtingos, naudojant Stjudento (t) testą. Tam, kad tai patikrinti bus skaičiuojama T statistika. Pirmą kartą duomenų požymių atrinkimui panaudotas neraiškaus integralo metodas su pilnuoju matu. Visi gauti eksperimentų rezultatai pateikti paveiksluose ir apibendrinti lentelėse. Magistrinio darbo išvadose pateiktas trumpas gautų rezultatų aprašymas. / The process of finding features that meet the given constrains out of a large group of features is called feature reduction. The reduction concept can be divided into feature selection and feature extraction techniques. The feature selection approach selects the independent features that provide sufficient information for a satisfactory separation between the different situations we want to discriminate. The physical values of selected features remain unchanged. The redundancy of features might be identified by a feature clustering and selection algorithm or we might remove features with the highest correlation. The algorithm removes similar features. This implies a faster training of consequent classifiers on reduced feature space. The feature extraction method works in opposite. Hereby, the features are projected onto a set of reduced feature space by some transformation function. The features in transformed space are no longer representing the same physical meaning as in original space. The transformation function is an analytical function and the challenge is to find representative and informative transformation for the given feature set. Very well known techniques are: the principal components analysis (PCA) and dimensionality reduction by auto-associative mapping using MLP neural. Four methods for features space reduction were analyzed in this work. All these methods have been used with four publicly available databases and applied to very well known k-nearest neighbor... [to full text]

Šiame darbe tiriamos skystojo kristalo su integruotomis kobalto nanodalelėmis optinės savybės. Panaudotos medžiagos: skystasis kristalas 5CB (penkiakomponentis cianobifenilas) ir kobalto nanodalelės kurių dydis 10nm. Tiriami pavyzdėliai su skirtingomis kobalto koncetracijomis (0,05%, 0,092%, 1,04%) skystajame kristale. Išmatuoti sugerties ir LD intensyvumo spektrai bangų ruože nuo 250 iki 700nm. / In this work I studied optical and manetooptical features of liquid crystal (LC) with integrated magnetic particles in magnetic field. I observed three different samples of LC with cobalt nanoparticles. Samples were made of LC pentyl-cyanobifenyl (5CB) and ferromagnetic (cobalt) particles of about 10nm. Each sample has a different concentration of cobalt nanoparticles (0,05%, 0,092%, 1,04%). All observations were made with Perkin-Elmer UV-VIS-NIR lambda 19 and Jasco spectrometer at room temperature and wavelength ranges from 250 to 700nm. My results show that low magnetic field till 0,2T is required to change cobalt-LC suspension optical features. Shift to IR region a: 17nm, 28nm and 31nm depending from cobalt concentration are detected. Different magnetic field makes unequal influence to samples with various concentrations of cobalt nanoparticles. From experiment I found that increasing of magnetic field till 0,2T, it shifts the absorption line to longer wavelength. From results follows that the magnetically controlled optical characteristic is very promising for magnetically controlled LC devices and information processing.Pavel Cyganok Magnetooptical features of flexible system, nanoparticle – liquid crystal.

To positively identify marine mammals using passive acoustics, large volumes of data are often collected that need to be processed by a trained analyst. To reduce acoustic analyst workload, an automatic detector can be implemented that produces many detections, which feed into an automatic classifier to significantly reduce the number of false detections. This requires the development of a robust classifier capable of performing inter-species classification as well as discriminating cetacean vocalizations from anthropogenic noise sources. A prototype aural classifier was developed at Defence Research and Development Canada that uses perceptual signal features which model the features employed by the human auditory system. The dataset included anthropogenic passive transients and vocalizations from five cetacean species: bowhead, humpback, North Atlantic right, minke and sperm whales. Discriminant analysis was implemented to replace principal component analysis; the projection obtained using discriminant analysis improved between-species discrimination during multiclass cetacean classification, compared to principal component analysis. The aural classifier was able to successfully identify the vocalizing cetacean species. The area under the receiver operating characteristic curve (AUC) is used to quantify the two-class classifier performance and the M-measure is used when there are three or more classes; the maximum possible value of both AUC and M is 1.00 – which is indicative of an ideal classifier model. Accurate classification results were obtained for multiclass classification of all species in the dataset (M = 0.99), and the challenging bowhead/ humpback (AUC = 0.97) and sperm whale click/anthropogenic transient (AUC = 1.00) two-class classifications.

Tiriamojo darbo tema yra ypač aktuali, todėl, kad ateityje bus susiduriama su elektros energijos stygiumi ir dideliu kainų šuoliu. Šiuo metu pasaulyje beveik visų tipų energijos kainos kyla dėl žaliavos stygiaus. Energijos taupymu reikia susirūpinti jau šendien, todėl manau, kad saulės energija yra puiki alternatyva kitoms energijos rūšims. Saulė yra atsinaujinantis energijos šaltinis kuris neteršia aplinkos, be to saulės energija gali sutaupyti nemažai lėšų gyvenamųjų namų savininkams. Šio darbo metu buvo ištirtos Lietuvos galimybės plėtoti saulės energijos technologijas, bei panaudojimo galimybes. Darbo metu buvo aprašyta atsinaujinančioji saulės energija, ištirti Lietuvos saulės energijos ištekliai ir nustatytos tinkamiausios vietos saulės energijos panaudojimui. Darbo metu buvo tiriami saulės kolektoriai ir saulės fotoelementai, jų veikimo principai, savybės ir panaudojimo galimybės. Be to buvo lyginami tarpusavyje kelių tipų saulės fotoelemenatai, vertinamos fotoelementų atsipirkimo galimybės. / Investigative work is important, therefore, that the future will be faced with power shortages and significant price increases. Currently, almost all types of world energy prices caused raw material shortages. Energy savings should be cause for concern today already, so I think that solar energy is a great alternative to other types of energy. The sun is a renewable energy source which does not pollute the environment, as well as solar energy can save you considerable amount of money to owners of residential houses. This work has explored the possibility of Lithuania to develop solar energy technologies, and usability. This work was described in the renewable solar energy have been examined in Lithuania solar energy resources, and determine the most appropriate local use of solar energy development. Work was to investigate photocells and solar panels, its operating principles, features, usability. Also, a comparison between several types of photocells and assessed the possibility of payback.

Šiuolaikinėje industrinėje visuomenėje, kai susiklostė sudėtingos ekonominės sąlygos, iš esmės pakito ir bendravisuomeninė šeimos samprata. Vaikas kasdien suvokia realią tikrovę ir pats joje dalyvauja perimdamas iš tėvų įvairias elgesio, veiklos, charakterio savybes. Pakitusiose socialinėse ekonominėse sąlygose, tam tikros grupės žmonių jaučiasi nesaugios, joms sunku prisitaikyti prie šiuolaikinio gyvenimo tempo, adaptuotis prie socialinių ekonominių ir politinių pokyčių. Ypatingai didelis nedarbo lygis išryškino šeimų, gaunančių mažas pajamas, socialines problemas.Tyrime dalyvavo 185 apklaustieji: 87 tėvai ir 18 ikimokyklinio ugdymo pedagogų, iš Kauno miesto Dainavos mikrorajono ikimokyklinio ugdymo įstaigų, kurie stebėjo ir įvertino 80 vaikų elgesį. / In modern industrial society, with difficult economic conditions, the family concept has been substantially altered. A child on a daily basis understands the reality and takes part in it taking over the characteristics of parental behavior, actions and temper. Certain groups of people feel unsafe in changed socio-economic conditions. They are difficult to adapt to the pace of modern life, to the socio-economic and political changes. Extremely high unemployment highlighted social problems of the families with low income The study involved 185 respondents: 87 parents and 18 preschool teachers from the preschools of Kaunas Dainava district; who monitored and evaluated the behavior of 80 children.