Tiesą sakant, priklausomybė nuo pinigų ir valdžios yra dvi pagrindinės priežastis neskaidriam ekonominiam sektoriui susiformuoti. Kad ir kaip bebūtų keista, gyvenimo faktas – tas, jog dideliam pasaulio populiacijos procentui, šešėlinis verslas tampa išgyvenimo priemone, nors Lietuvos Pramonininkų Konfederacijos pareiškimu: „<...> neapskaityta ekonominė veikla, neoficialus darbas, sukčiavimas ir mokesčių vengimas ne tik kenkia šalies įvaizdžiui, ardo oficialią rinką ir konkurencingumą, bet, kartu, negailestingai griauna sąžiningą verslą<...>“. Šio darbo siekis – įvertinti ir suprasti Lietuvos šešėlinės ekonomikos poveikį verslo sėkmei arba legaliai veiklai. Atliktų tyrimų uždaviniai – interpretuoti bendrą pastarojo ekonominio reiškinio kilmės ir šaltinių analizę, apžvelgti, kaip jis atsispindi pinigų statistikoje bei kokia įtaka turi oficialiam verslui, naudojant Tanzi ir Gutmman monetarinius metodus, koreliacija bei Eilat /Zinnes regresijos funkcija. Tyrimų rezultatai apsibrėžtam periodui, nuo 1995 iki 2007 metų, parodė, jog tarp apskaitytos ir neapskaitytos ekonomikų vyrauja neigiamas ryšys, kuris išreiškia substituto efekto pozicionavimą pajamų efekto atžvilgių. Vadinasi, apskaitytoms pajamoms sumažėjus 1LT, šešėlinės pajamos išauga 16 centų. Tuo tarpu, 1LT išaugus apskaitytam BVP, neoficialusis - sumažėja 43 centais. Kitą vertus, monetarinis metodas parodė, jog šešėlinė ekonomika yra glaudžiai susijusi su oficialiais kintamaisiais, todėl norint sumažinti neapskaityto... [toliau žr. visą tekstą] / Actually, - addiction to money and governance are two main reasons why legal shadow economy arises. As strange it seems, it has not only negative impact, but also a positive one to the official economy. And it‘s a fact of life, that for a large part of the worlds population, the "shadow economy" has become a means of survival, while, accordingly to The Confederation of Lithuanian Industrialists declaration, “<…> unaccounted economic activities, illegal jobs, cheating and tax evasion harm the state, disturb the market and competition and demonstrably ruin and discredit fair business <...>”. The aim of this work - is to evaluate and understand the impact of Lithuania's shadow economy to the official one. The main goals of the research – interpellate the analysis of shadow economy genesis and origins and review how it reflects in nummary statistics or how influence officially accounted economy, using Tanzi’s and Gutmann’s monetary approaches, correlation and Eilat/Zinnes regression function. Exploration findings for the entire period of 1995-2007 confirms, that the unrecorded and recorded economies in Lithuania are negatively related, suggesting that the substitution effect dominates the income effect. And 1 LT fall in recorded income is associated with a 16 cent increase in the unrecorded economy and that a 1LT increase in recorded GDP is associated with a 43 cent decline in unrecorded income. On the other hand, monetary approach showed that shadow economy is closely related... [to full text]

Analyzing the structure of a dataset is a challenging problem in high-dimensions as the volume of the space increases at an exponential rate and typically, data becomes sparse in this high-dimensional space. This poses a significant challenge to machine learning methods which rely on exploiting structures underlying data to make meaningful inferences. This dissertation proposes the <i>n</i>-TARP method as a building block for high-dimensional data analysis, in both supervised and unsupervised scenarios.<div><br></div><div>The basic element, <i>n</i>-TARP, consists of a random projection framework to transform high-dimensional data to one-dimensional data in a manner that yields point separations in the projected space. The point separation can be tuned to reflect classes in supervised scenarios and clusters in unsupervised scenarios. The <i>n</i>-TARP method finds linear separations in high-dimensional data. This basic unit can be used repeatedly to find a variety of structures. It can be arranged in a hierarchical structure like a tree, which increases the model complexity, flexibility and discriminating power. Feature space extensions combined with <i>n</i>-TARP can also be used to investigate non-linear separations in high-dimensional data.<br></div><div><br></div><div>The application of <i>n</i>-TARP to both supervised and unsupervised problems is investigated in this dissertation. In the supervised scenario, a sequence of <i>n</i>-TARP based classifiers with increasing complexity is considered. The point separations are measured by classification metrics like accuracy, Gini impurity or entropy. The performance of these classifiers on image classification tasks is studied. This study provides an interesting insight into the working of classification methods. The sequence of <i>n</i>-TARP classifiers yields benchmark curves that put in context the accuracy and complexity of other classification methods for a given dataset. The benchmark curves are parameterized by classification error and computational cost to define a benchmarking plane. This framework splits this plane into regions of "positive-gain" and "negative-gain" which provide context for the performance and effectiveness of other classification methods. The asymptotes of benchmark curves are shown to be optimal (i.e. at Bayes Error) in some cases (Theorem 2.5.2).<br></div><div><br></div><div>In the unsupervised scenario, the <i>n</i>-TARP method highlights the existence of many different clustering structures in a dataset. However, not all structures present are statistically meaningful. This issue is amplified when the dataset is small, as random events may yield sample sets that exhibit separations that are not present in the distribution of the data. Thus, statistical validation is an important step in data analysis, especially in high-dimensions. However, in order to statistically validate results, often an exponentially increasing number of data samples are required as the dimensions increase. The proposed <i>n</i>-TARP method circumvents this challenge by evaluating statistical significance in the one-dimensional space of data projections. The <i>n</i>-TARP framework also results in several different statistically valid instances of point separation into clusters, as opposed to a unique "best" separation, which leads to a distribution of clusters induced by the random projection process.<br></div><div><br></div><div>The distributions of clusters resulting from <i>n</i>-TARP are studied. This dissertation focuses on small sample high-dimensional problems. A large number of distinct clusters are found, which are statistically validated. The distribution of clusters is studied as the dimensionality of the problem evolves through the extension of the feature space using monomial terms of increasing degree in the original features, which corresponds to investigating non-linear point separations in the projection space.<br></div><div><br></div><div>A statistical framework is introduced to detect patterns of dependence between the clusters formed with the features (predictors) and a chosen outcome (response) in the data that is not used by the clustering method. This framework is designed to detect the existence of a relationship between the predictors and response. This framework can also serve as an alternative cluster validation tool.<br></div><div><br></div><div>The concepts and methods developed in this dissertation are applied to a real world data analysis problem in Engineering Education. Specifically, engineering students' Habits of Mind are analyzed. The data at hand is qualitative, in the form of text, equations and figures. To use the <i>n</i>-TARP based analysis method, the source data must be transformed into quantitative data (vectors). This is done by modeling it as a random process based on the theoretical framework defined by a rubric. Since the number of students is small, this problem falls into the small sample high-dimensions scenario. The <i>n</i>-TARP clustering method is used to find groups within this data in a statistically valid manner. The resulting clusters are analyzed in the context of education to determine what is represented by the identified clusters. The dependence of student performance indicators like the course grade on the clusters formed with <i>n</i>-TARP are studied in the pattern dependence framework, and the observed effect is statistically validated. The data obtained suggests the presence of a large variety of different patterns of Habits of Mind among students, many of which are associated with significant grade differences. In particular, the course grade is found to be dependent on at least two Habits of Mind: "computation and estimation" and "values and attitudes."<br></div>

Šiuo metu vyraujanti pasaulinė ekonominė krizė, taip pat ankstesni bendrovių bankrotų pavyzdžiai (tokių kaip Enron, Parmalat) signalizuoja apie būtinybę tinkamai sureguliuoti bendrovių valdymo teisinę bazę, o ypač aspektus susijusius su bendrovės akcininkų ir valdymo organo santykiais. Todėl šiame magistro darbe yra analizuojamos teisinės priemonės, kurios padeda sumažinti interesų konfliktus kylančius tarp bendrovių, kurių vertybiniais popieriais yra prekiaujama reguliuojamoje rinkoje, akcininkų ir valdymo organo. Šiam tikslui pasiekti yra išskiriamos penkios teisinio reguliavimo sritys: bendrovių kontrolės rinkos ir bendrovių perėmimo, informacijos atskleidimo, valdymo organo narių finansinio skatinimo, valdymo organo struktūros bei bendrovės akcininkų teisių teisinis reguliavimas. Kiekviena reguliavimo sritis yra aptariama dviem aspektais, pirmiausia, analizuojant Europos Sąjungos lygiu egzistuojantį teisinį reguliavimą, po to vertinant tokio reguliavimo įgyvendinimą Lietuvos Respublikoje bei pateikiant pastabas ir pasiūlymus. Darbe padaroma išvada, kad norint sumažinti neigiamas pasekmes atsirandančias dėl nuosavybės teisės ir valdymo atskyrimo bendrovėse, reikia, kad visos aukščiau išvardintos priemonės papildytų viena kitą ir būtų taikomos sistemiškai. / The ongoing economic crisis around the world and the recent events in corporate bankruptcy sector (including Enron and Parmalat cases) have shown a clear signal to regulate more efficiently the corporate governance laws and especially the relations between shareholders and the governance body of the company. This thesis paper addresses the regulatory framework issues, which mitigate the conflict of interests between the shareholders and the governance body of publicly traded companies. Five legal instruments are analyzed in order to achieve this objective: market for corporate control and takeovers, information disclosure, director remuneration, structure of governance body and shareholder empowerment. Each legal instrument is analyzed from two legal perspectives, first, the European Union legal framework is described and then analysis concentrates on the implementation of European law in the Republic of Lithuania. Comments and proposals are given to existing implementation problems. The conclusion emphasizes that a systematic use of all the above mentioned legal instruments is required in order to mitigate the costs of separation of ownership and control in publicly traded companies.

Les nématodes à galles demeurent l'un des problèmes les plus graves des ‎agriculteurs de serres du Liban et du Moyen-Orient. Dans le passé, la fumigation du sol au ‎bromure de méthyle a été considérée comme la meilleure mesure de contrôle contre ces ‎nématodes. Toutefois, à la lumière de l'élimination globale du bromure de méthyle, l'accès ‎aux alternatives efficaces et durables est devenu une nécessité essentielle.‎L'objectif de cette étude est d'évaluer l'efficacité des deux engrais verts, le radis ‎huileux (Raphanus sativus oleifera) et à la roquette (Eruca vesicaria sativa) appliquées ‎avec ou sans bâche en plastique, séparément et en combinaison avec Oxamyl, dans la ‎gestion des nématodes à galles en cultures de concombres de serre. En outre, cette étude ‎vise à évaluer la faisabilité financière de la technique de biofumigation avec les deux ‎cultures utilisées et de la rentabilité finale de ces engrais verts en termes de taux coût-profit ‎par rapport au bromure de méthyle.‎A cette fin, trois expériences sur le terrain ont été menées dans des serres ‎commerciales, situées sur la zone côtière du Liban.‎Dans les deux expériences A et B, des résultats cohérents ont été enregistrés en ‎termes de production de rendements significativement plus élevés et de la réduction des ‎populations de nématodes avec les engrais verts‎ utilisés avec ou sans bâche en plastique, ‎par rapport au témoin non traité.‎Quant aux résultats obtenus par les engrais verts‎ par rapport ‎ au bromure de ‎méthyle, dans l'expérience A, le rendement produit par le bromure de méthyle était ‎significativement plus élevé que celui du radis huileux avec bâche en plastique. ‎Cependant, la différence n'était pas significative entre la réduction de la population de ‎nématodes résultant du bromure de méthyle et celle du radis huileux avec bâche en ‎plastique. Les différences du rendement ainsi que la réduction des nématodes étaient ‎significatives entre le bromure de méthyle et le radis huileux sans bâche en plastique.‎Dans l'expérience B, aucune différence significative n'a été observée dans le ‎rendement ni la réduction de la population de nématodes entre aucun des deux engrais ‎verts‎ utilisés avec bâche en plastique et le bromure de méthyle. Ces différences étaient ‎significativement en faveur du bromure de méthyle uniquement lorsque le radis huileux a ‎été utilisé sans bâche en plastique.‎Dans l'expérience C, où Vydate (Oxamyl) a été appliqué à la dose de 1 litre par 1,000 ‎m2 à tous les traitements, il n'y avait pas de différence significative dans le rendement ni la ‎réduction de la population de nématodes entre chacun des deux engrais verts utilisés avec ‎ou sans bâche en plastique et le bromure de méthyle.‎L'analyse coût-profit menée sur tous les traitements appliqués dans les 3 ‎expériences a montré que dans tous les cas, tous les traitements appliqués, qu'ils soient ‎chimiques, non-chimique (avec ou sans bâche en plastique) ou en association ont produit ‎des bénéfices nets supérieurs au bromure de méthyle, même lorsque le rendement produit ‎par le bromure de méthyle était significativement plus élevée.‎L'utilisation du plastique pour couvrir les radis huileux a généralement produit de ‎meilleurs résultats en termes de production de rendements plus élevés, une meilleure ‎réduction des populations de nématodes à galles dans le sol, ainsi conduisant à des ‎augmentations raisonnables des profits nets.‎A la base de ces résultats et à la lumière de l'élimination globale du bromure de ‎méthyle, on peut conclure que l'utilisation du radis huileux et la roquette comme engrais ‎verts avec bâche en plastique peut être considéré comme un outil alternatif pour la gestion ‎des nématodes à galles dans la production de concombres de serre dans les conditions ‎libanaises.‎ / Root-knot nematodes remain one of the most serious problems faced ‎by ‎greenhouse farmers of Lebanon and the Middle East region. In the past, soil fumigation ‎with methyl bromide has been considered as ‎the best control measure against root-knot ‎nematodes. However, in the light of the global phase out of methyl bromide, finding ‎efficient and viable alternatives is an essential necessity.‎The objective of this study is to evaluate the efficacy of the two biofumigation ‎crops ‎Oil Radish (Raphanus sativus oleifera) and Arugula (Eruca vesicaria sativa) applied ‎with ‎and without plastic tarp, separately and in combination with Oxamyl in the ‎management of ‎the root-knot nematodes in greenhouse cucumber crops. Additionally, this ‎study aimed at ‎assessing the financial feasibility of the biofumigation technique with the ‎two cops used ‎and the final profitability of these green manure crops in terms of cost to ‎benefit ratio as ‎compared to methyl bromide.‎For this purpose, three field experiments were carried out in ‎commercial ‎greenhouses situated on the coastal zone of Lebanon.‎In both experiments A & B consistent results were recorded in terms of production ‎of ‎significantly higher yields and reduction of nematode population with the ‎biofumigation ‎crops used whether with or without plastic cover, as compared to untreated ‎fallow.‎As to the results achieved by the biofumigation crops with respect to methyl ‎bromide, ‎in experiment A yield produced by methyl bromide was significantly higher than ‎oil radish ‎with plastic cover. However, no significant difference was found between ‎reduction of ‎nematode population resulting from methyl bromide and oil radish with plastic ‎cover. ‎Difference was significant between methyl bromide and oil radish without plastic ‎cover in ‎both yield and reduction of nematodes.‎In experiment B no significant difference was observed in neither yield nor ‎reduction ‎of nematode population between any of the two biofumigation crops used with ‎plastic ‎cover and methyl bromide. These differences were significantly in favor of methyl ‎bromide ‎only when oil radish was used without plastic cover.‎In experiment C where Vydate (Oxamyl) was incorporated at the rate of 1 liter ‎per ‎‎1,000 m2 to all treatments, there was no significant difference in neither yield nor ‎reduction ‎of nematode population between any of the two biofumigation crops used with or ‎without ‎plastic cover.‎Cost-benefit analysis made on all treatments applied in the 3 experiments ‎showed ‎that in all cases, all treatments applied, whether chemical, non-chemical (with or ‎without ‎plastic cover) or in combination have produced higher net profits than methyl ‎bromide, ‎even when yield produced by methyl bromide was significantly higher.‎Use of plastic for covering oil radish has generally produced ‎better results in terms ‎of ‎production of higher yields, better reduction of soil ‎populations of root-knot nematodes‏‎ ‎and ‎‏leading to ‎‏reasonable increases of net profits.‎Based on these findings and in the light of global phase out of methyl bromide, ‎it ‎can be concluded that the use of oil radish and arugula as biofumigation crops with ‎plastic ‎cover can be considered as ‎an alternative management tool for the root-knot ‎nematode in ‎greenhouse cucumber ‎production under Lebanese conditions.‎