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Search Results: 1 - 10 of 13 matches for " Justas Gedvilas "
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Corporate Governance of SOEs and Performance in Transition Countries. Evidence from Lithuania  [PDF]
Claudia Curi, Justas Gedvilas, Ana Lozano-Vivas
Modern Economy (ME) , 2016, DOI: 10.4236/me.2016.712126
Abstract: This paper investigates whether and to what extent corporate governance mechanisms affect the efficiency of State Owned Enterprises (SOEs) operating in transition economies. Furthermore, it examines the relationship between corporate governance practice and its impact on both wholly state run SOEs and majority state run SOEs. We employed a unique dataset of corporate governance ratings (related to quality of transparency, quality of board, and quality of strategic planning, implementation and control) of commercial Lithuanian SOEs relating to the period following the introduction of the corporate governance reforms in the years 2012-2013. In order to investigate our research hypotheses, we set up a two-stage empirical research strategy that combined a non-parametric efficiency estimator (i.e., Data Envelopment Analysis) with a bootstrapped truncated regression. We built two aggregate indexes of corporate governance ratings to represent one dimension of corporate governance quality. We then ran a battery of regressions using both the aggregated and the single corporate governance indexes as independent variables. First, the paper finds that the wholly state ownership model of SOEs is positively correlated to efficiency (i.e., wholly SOEs are more efficient than majority SOEs). Moreover, overall corporate governance practices are efficiency-enhancing; more specifically, board quality and strategic planning seem to be effective internal governance mechanisms in promoting overall organizational efficiency. Interestingly, we uncovered that there exists a relationship between concentration of ownership and corporate governance practices, but this mitigated efficiency enhancement in wholly state run SOEs compared to majority state run SOEs. This effect was driven by the lower quality of the board. Overall, our findings illustrate that corporate governance reforms have enhanced efficiency, but wholly SOEs require a better implementation in order to achieve full efficiency gains.
Ice Shelves as Floating Channel Flows of Viscous Power-Law Fluids
Indranil Banik,Justas Dauparas
Physics , 2013,
Abstract: We attempt to better understand the flow of marine ice sheets. Treating ice as a viscous shear-thinning power law fluid, we develop an asymptotic (late-time) theory in two cases - the presence or absence of contact with sidewalls. Most real-world situations fall somewhere between the two extreme cases considered. When sidewalls are absent, we obtain the equilibrium grounding line thickness using a simple computer model and have an analytic approximation. For shelves in contact with sidewalls, we obtain an asymptotic theory, valid for long shelves. Our theory is based on the velocity profile across the channel being a generalised version of Poiseuille flow, which works when lateral shear dominates the force balance. We determine when this is. We conducted experiments using a laboratory model for ice. This was a suspension of xanthan in water, at a concentration of 0.5% by mass. The lab model has $n \approx 3.8$ (similar to that of ice). The experiments agreed extremely well with our theories for all relevant parameters (front position, thickness profile, lateral velocity profile, longitudinal velocity gradient and grounding line thickness). We also saw detailed features similar to natural systems. Thus, we believe we have understood the dominant force balance in both types of ice shelf. Our work has implications for the collapse of ice shelves, such as Larsen B. We show roughly why it collapsed, based on an instability whereby breaking off part of the shelf exposes more area to the ocean and leads to an increased rate of iceberg formation. The complete collapse of the shelf leads to the loss of buttressing exerted by the sidewalls and an increase in the rate of flow. This can be estimated using our equations and the initial rate of flow and topography. Ice tongues are much more stable but ice sheets which enter the ocean without feeding an ice shelf may be unstable.
Networking in the Transport Sector: Inter-Firm vs Intra-Firm Perspective Transporto sektoriaus tinklaveika: interorganizacijos ir intraorganizacijos tinklaveikos perspektyva
Justas Nugaras,Asta Radzevi?ien?
Science – Future of Lithuania , 2010, DOI: 10.3846/mla.2010.037
Abstract: Changes in the global economic environment have a huge impact on the transport and logistics sector. Experts in the sector emphasize the role of collaboration in order to reach common goals. In theory such phenomena is analyzed through the networking viewpoint. Among the major groups of players in the sector, two types of networks are dominant: inter-firm networking and intra-firm networking. Empirical pilot research is done by comparing two types of networking in global and local companies. Following the results of the pilot research the conclusion was made that inter-firm networking and intra-firm networking in the companies complement each other and require further research. Article in English Globalios ekonomikos poky iai tur jo didel tak transporto ir logistikos sektoriaus pl trai. Sektoriaus ekspertai pabr ia i augus bendradarbiavimo vaidmen siekiant bendr tiksl – toks bendradarbiavimas vadybos teorijoje da niausiai nagrin jamas i tinklaveikos perspektyvos. Pagrindini veik j sektoriuje analiz parod , kad du tinklaveikos tipai yra vyraujantys: interorganizacin tinklaveika ir intraorganizacin tinklaveika. Autori atliktas empirinis pilotinis tyrimas palygina dviej tip tinklaveikas vietin je ir globalioje transporto mon je. Tyrimo rezultatai parod , kad inter-firm ir intra-firm tinklaveika papildo viena kit ir objekt tirti verta toliau. Straipsnis angl kalba
On the value-distribution of the Riemann zeta-function on the critical line
Justas Kalpokas,J?rn Steuding
Mathematics , 2009,
Abstract: We investigate the intersections of the curve $\mathbb{R}\ni t\mapsto \zeta({1\over 2}+it)$ with the real axis. We show that if the Riemann hypothesis is true, the mean-value of those real values exists and is equal to 1. Moreover, we show unconditionally that the zeta-function takes arbitrarily large real values on the critical line.
Comparative Research into Multicomponent Camelina Sativa and Rapeseed Methyl Ester Biofuels
Justas ?aglinskis,Paulius Rapalis,Vygintas Dauk?ys
Science – Future of Lithuania , 2012,
Abstract: The article presents the results of comparative motor research on FAME biofuels using diesel engine VALMET 320 DMG. Energy (ηe, be) and environmental parameters (CO2, CO, NOx, HC, SM) of the engine were estimated. The obtained data on motor research into new biofuels show that the properties of Camelina sativa biofuels are as good as those observed in standardized rapeseed methyl ester biofuels. In case of using Camelina sativa biofuels blends VME and ZME at different engine loads, exhaust emissions from gas smoke could be reduced up to 10% and 30% accordingly comparing with mineral diesel. When the engine is fueled with tested biofuel blends, carbon monoxide emissions decrease by about 5–6%, and the factor for effective performance increases by approximately 4%. In all range of engine loads, an increase in nitrogen oxide emissions reaching 2–3% was observed. In all cases of using biofuel blends, carbon dioxide emissions keep close to the application of mineral diesel.
Analysis of the Influence of the Modernized Bitumen Batching System on the Composition of the Hot Mix Asphalt Mixture Modernizuotos bitumo dozavimo sistemos takos kar tojo mai ymo asfalto mi inio sud iai tyrimas
Justas Bra?iūnas,Henrikas Sivilevi?ius
Science – Future of Lithuania , 2010, DOI: 10.3846/mla.2010.115
Abstract: The weighted mass of a binder in the bucket of the bitumen batcher of a batch-type asphalt plant should be such that its percentage of hot mix asphalt (HMA) mixture lot would comply with the design amount of the job-mix formula in all mix batches. A bitumen batcher does not always weigh bitumen portions precisely. Their mass deviations from the amount determined by the project and its variation impair HMA composition and performance. The paper provides data on a statistical evaluation of bitumen batcher modernization performed at Lithuanian enterprise LL“. The article analyzes differences in the structures of reconstructed and not reconstructed bitumen batching systems and presents methods for determining modernization effectiveness. The paper also focuses on the effectiveness of the batching system, determining deviations from bitumen content in subsamples taken and extracted everyday during two seasons (before and after batcher‘s modernization) of producing HMA from the value of job-mix formula and comparing them to the values of tolerances. Article in Lithuanian Asfaltbetonio mai ytuvo (ABMA) bitumo dozavimo sistema (BDS) priskiriama sud tingam vamzdyn transportui. Ji privalo ne tik laikyti reikiamos temperatūros bitum , j tiekti i talpykl mai ykl , bet ir tiksliai dozuoti ri ikl leid iant minimaliai pakisti jo savyb ms. Periodinio veikimo asfaltbetonio mai ytuve bitumo dozatoriaus bakelyje atsverto ri iklio mas turi būti tokia, kad jo procentinis kiekis kar tojo mai ymo asfalto (KMA) mi inio partijos visuose mai iniuose atitikt projektin kiek , nustatyt darbin je mi inio formul je (DMF). Ne visada bitumo dozatorius tiksliai ir glaud iai atsveria bitumo dozes, o tai blogina KMA mi inio sud t ir savybes. Pateikti Lietuvos LL“ mon s (pavadinimas pakeistas) BDS patobulinti statistinio vertinimo duomenys. I analizuoti nepatobulintos ir patobulintos BDS konstrukcij skirtumai ir pateikta modernizavimo efektyvumo nustatymo metodika. BDS kokyb tirta per du KMA mi inio gamybos sezonus (prie ir po modernizavimo). Kiekvien dien imt ir ekstrahuot tūrini mini bitumo kieki nuokrypi nuo DMF vert s lygintos su tolerancij vert mis. Straipsnis lietuvi kalba
Fabrication of Periodic Micro-Structures by Multi-Photon Polymerization Using the Femtosecond Laser and Four-Beam Interference
Evaldas STANKEVI?IUS,Mangirdas MALINAUSKAS,Mindaugas GEDVILAS,Bogdan VOISIAT
Materials Science , 2011, DOI: 10.5755/j01.ms.17.3.587
Abstract: Multi-photon polymerization by interference is a promising technique for mass fabrication of 3D periodic micro-structures over large areas, which can be used in various fields such as biomedicine (cell growing), photonics (photonics crystals), etc. As direct laser writing approach is a relatively slow process, fabrication of periodic structures by interference field of a few laser beams can be a significantly faster alternative route of parallel processing. The periodic structures are produced by the single laser exposure over the whole irradiated area. In this paper we present examples how periodic micro-structures can be fabricated over a large area by multi-photon polymerization in a negative photopolymer SZ2080 (ORMOSIL) using four-beam interference of a femtosecond laser. http://dx.doi.org/10.5755/j01.ms.17.3.587
Temporal variation of extreme precipitation events in Lithuania
Egidijus Rimkus,Justas Ka?ys,,Arūnas Bukantis,,Aleksandras Krotovas
Oceanologia , 2011,
Abstract: Heavy precipitation events in Lithuania for the period 1961-2008 were analysed. The spatial distribution and dynamics of precipitation extremes were investigated. Positive tendencies and in some cases statistically significant trends were determined for the whole of Lithuania. Atmospheric circulation processes were derived using Hess & Brezowski's classification of macrocirculation forms. More than one third of heavy precipitation events (37%) were observed when the atmospheric circulation was zonal. The location of the central part of a cyclone (WZ weather condition subtype) over Lithuania is the most common synoptic situation (27%) during heavy precipitation events. Climatic projections according to outputs of the CCLM model are also presented in this research. The analysis shows that the recurrence of heavy precipitation events in the 21st century will increase significantly (by up to 22%) in Lithuania.
Negative values of the Riemann zeta function on the critical line
Justas Kalpokas,Maxim A. Korolev,J?rn Steuding
Mathematics , 2011, DOI: 10.1112/S0025579313000090
Abstract: We investigate the intersections of the curve $\mathbb{R}\ni t\mapsto \zeta({1\over 2}+it)$ with the real axis. We show unconditionally that the zeta-function takes arbitrarily large positive and negative values on the critical line.
Structural and Phase Transformations in Water-Vapour-Plasma-Treated Hydrophilic TiO2 Films
L. Pranevicius,M. Urbonavicius,S. Tuckute,K. Gedvilas,T. Rajackas,L. L. Pranevicius,D. Milcius
Advances in Materials Science and Engineering , 2012, DOI: 10.1155/2012/592485
Abstract: We have investigated structural and phase transformations in water-vapor-plasma-treated 200–300?nm thick Ti films, maintained at room temperature, by injecting water vapor into radio frequency (RF) plasma at different processing powers. Scanning electron microscopy (SEM) combined with optical microscopy and surface nanotopography analysis were used to view tracks of adsorbed water layers and to detect bulges or blisters appeared on the surface of treated samples. Rough surfaces with different size of holes (5–20?μm) through the entire film thickness have been observed. X-ray diffraction results show that the oxidation rate of Ti film drastically increases in the presence of an adsorbed water on the hydrophilic layer. It is assumed that the defining factor which controls oxidation kinetics is the hydroxyl radicals formation. 1. Introduction Exposition of Ti surfaces in water vapor results in the formation of an adsorbed layer on the surface. Rapid diffusion on the surface maintains quasiequilibrium between the molecules bound to islands and isolated adsorbed water molecules. Water molecules oxidize Ti atoms ( + ( ) H2O = TiO2 + ( ) H2). These possible oxidation reactions are highly thermodynamically favorable and form nanostructured hydrated titanium oxide layer [1]. It is known that the thermal oxidation of titanium by water vapor proceeds according to a linear-parabolic rate law resulting from a reaction-diffusion-mixed regime. The growth of TiO2 takes place by rapid diffusion of substitutional hydroxide ions generated at the gas-scale interface [2]. It is established [3] that the titanium coating exposed to ultraviolet light has the extraordinary property of complete wettability for water. The ultraviolet light removes some of the oxygen atoms from the surface of the titania, resulting in a patchwork of nanoscale domains where hydroxyl groups became adsorbed, which produces the superhydrophilicity. It is proved that the Ti3+ ions are closely associated with the hydrophilicity of TiO2 [4, 5]. Titanium coatings immersed in plasma are exposed to ultraviolet radiation and ion bombardment [6, 7]. Due to radiation coming from the plasma, oxygen atoms are preferentially removed from the surface of titania and the formation of suboxides as well as an oxygen deficient surface in the steady state is registered [8]. The water molecules arriving at the plasma activated surface due to hydrophilicity tend to spread out over the entire surface, as schematically shown in Figure 1. Figure 1: Formation of water layer on the hydrophilic surface: (a) adsorbed water on a
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