Railroad bridges and culverts in the United States are often subject to extreme floods, which have been known to washout sections of track and ultimately lead to derailments. The potential for these events is particularly high in the western U.S. due to the lack of data, inadequate radar coverage, and the high spatial and temporal variability of storm events and terrain. In this work, a hydrologic model is developed that is capable of effectively describing the rainfall-runoff relationship of extreme thunderstorms in arid and semi-arid regions. The model was calibrated and validated using data from ten storms at the semi-arid Walnut Gulch Experimental Watershed. A methodology is also proposed for reducing the amount of raingages required to provide acceptable inputs to the hydrologic model, and also determining the most appropriate placement location for these gages. Results show that the model is capable of reproducing peak discharges, peak timings, and total volumes to within 22.1%, 12 min, and 32.8%, respectively. Results of the gage reduction procedure show that a decrease in the amount of raingages used to drive the model results in a disproportionally smaller decrease in model accuracy. Results also indicate that choosing gages using the minimization of correlation approach that is described herein will lead to an increase in model accuracy as opposed to selecting gages on a random basis.

No description available.

Precipitation phase is fundamental to a catchment’s hydrological response to precipitation events in cold regions and is especially variable over time and space in complex topography. Phase is controlled by the microphysics of the falling hydrometeor, but microphysical calculations require detailed atmospheric information that is often unavailable and lacking from hydrological analyses. In hydrology, there have been many methods developed to estimate phase, but most are regionally calibrated and many depend on air temperature (Ta) and use daily time steps. Phase is not only related to Ta, but to other meteorological variables such as humidity. In addition, precipitation events are dynamic, adding uncertainties to the use of daily indices to estimate phase. To better predict precipitation phase with respect to meteorological conditions, the combined mass and energy balance of a falling hydrometeor was calculated and used to develop a model to estimate precipitation phase. Precipitation phase and meteorological data were observed at multiple elevations in a small Canadian Rockies catchment, Marmot Creek Research Basin, at 15-minute intervals over several years to develop and test the model. The mass and energy balance model was compared to other methods over varying time scales, seasons, elevations and topographic exposures. The results indicate that the psychrometric energy balance model performs much better than Ta methods and that this improvement increases as the calculation time interval decreases. The uncertainty that differing phase methods introduce to hydrological process estimation was assessed with the Cold Regions Hydrological Model (CRHM). The rainfall/total precipitation ratio, runoff, discharge and snowpack accumulation were calculated using a single and a double Ta threshold method and the proposed physically based mass and energy balance model. Intercomparison of the hydrological responses of the methods highlighted differences between Ta based and psychrometric approaches. Uncertainty of hydrological processes, as established by simulating a wide range of Ta methods, reached up to 20% for rain ratio, 1.5 mm for mean daily runoff, 0.4 mm for mean daily discharge and 160 mm of peak snow water equivalent. The range of Ta methods showed that snowcover duration, snow free date and peak discharge date could vary by up to 36, 26 and 10 days respectively. The greatest hydrological uncertainty due to precipitation phase methods was found at sub-alpine and sub-arctic headwater basins and the least uncertainty was found at a small prairie basin.

Quantifying carbon emissions of water bodies at regional scale is required as recent studies revealed their contribution in carbon cycling is significant. This demands to scale up water bodies carbon emissions from local to regional scale using as accurate approach as possible. In this study data of carbon (CO2-C) fluxes for 80 sampled lakes were used to scale up to more than 3000 lakes and ponds over the catchment. The most appropriate method for upscaling was the one in which two factors of water body size and location (altitude) were involved and the uncertainties were quantified in an advanced approach (Monte Carlo model). Based on the estimates obtained in this method, the annual carbon emission from all water bodies (~ 500 km2) was about 2900 ton C yr-1 . About 62% of this annual emission was related to the large lake Torneträsk (334 km2) and another 38% to all other lakes and ponds (166 km2). Water bodies in subalpine region dominated (90%) total water bodies area and were the major contributor (97%) to the total carbon emissions of all water bodies. The remaining small contribution (3%) was for water bodies in the alpine region, which contains only 10% of total water bodies area. These data indicate that all water bodies smaller than the large lake Torneträsk especially the ones in the subalpine region have considerable contribution to the annual carbon emission of all water bodies. Considering water body size and altitude factors in the advanced upscaling method was appropriate to obtain accurate estimates.

Šiame magistro darbe yra analizuojama Lietuvos regionų esama ekonominė situacija bei pagrindinės priežastys, kurios lemia netolygią regionų plėtrą. Atlikta regionų teritorinių skirtumų analizė pagal egzistuojančius ūkio subjektus, tiesiogines užsienio bei materialines investicijas. Įvertinti Bendrojo vidaus produkto vienam gyventojui ir vienam užimtajam rodikliai, o taip pat atlikta regionų specializacijos bei lyginamojo pranašumo analizė. Patvirtinta tyrimo hipetezė, kad Lietuvos regionų ekonominių bei socialinių skirtumų augimą lemia kumuliatyvinis priežastingumo procesas, todėl siekiant įveikti šį procesą, reikalinga šalies parama, kuri skatintų ir finansuotų darbo jėgos mokymą bei investicijas į žmogiškąjį kapitalą. / This master’s final paper analyses available economic situation in Lithuania region and its main causes, that determine even development of regions. The paper presents a detailed analysis of differences in spatial economic activity described by territotial disparity of active economic subjects, investment in tangible fixed assets and foreign direct investment in regions. Estimation of the rate and speed of uneven growth is grounded on spatial disparity measurement of GDP per capita and GDP per worker. The hypothesis is formulated as follows- the source of increasing economical and social differences in Lithuanian regions is cumulative causation process- is confirmed. Political intervantion in promoting workplace training programs and accumulation of human capital stock is necessary to defeat this causation process.

Disertaciją sudaro įvadas, trys darbo skyriai bei svarbiausios darbo išvados ir pasiūlymai. Darbas remiasi sektorinės sisteminės analizės logika, pagal kurią nagrinėjama depresinių šalies regionų darbo rinkos plėtros problema suprantama kaip visos ūkinės sistemos regioninis ir darbo rinkos problemų pjūvis. Nuo bendriausiųjų temos klausimų aptarimo pirmajame darbo skyriuje – sampratos, klasifikavimo sistemos, konkrečių kriterijų, regionų ir darbo rinkos bei socialinės apsaugos sistemų plėtojimo patirties apibendrinimo – antrajame disertacijos skyriuje pereinama prie nagrinėjamos problemos ypatumus atspindinčių elementų analizės: remiantis statistiniais matematiniais metodais, atmetimo principu atrenkami patikimai, operatyviai probleminę ir depresinę padėtį charakterizuojantys rodikliai. Preliminariai išskirti probleminiai šalies regionai tiriami siekiant identifikuoti veiksnius, turinčius didžiausią įtaką depresinių šalies regionų darbo rinkos raidai. Problemos kompleksinės analizės finalas – trečiajame darbo skyriuje. Čia pagrindžiami depresinių šalies regionų darbo rinkos plėtros sprendimai, kurių kompleksinio taikymo sinergetinis efektas užtikrintų geresnius depresinių šalies regionų, o tuo pačiu ir visos šalies, socialinės ekonominės raidos rezultatus. / The scientific work consists of introduction, three working sections, conclusive findings. This dissertation work is based on the logics of sectoral analysis in accordance with which the analysed problem of labour market development in depressed regions of the country is understood as a regional cross-section of the entire economic system and of labour market problems. Starting with a discussion of the most general issues of the topic in the first working section – concept, classification system, generalisation of particular criteria, experience in the development of regions, labour market and social security systems, the author comes to the analysis of elements reflecting the peculiarities of the problem at issue, i.e., based on statistic mathematical methods and elimination principle, indicators are selected for reliable and operative characterisation of problematic and depressed situations. Pre-identified problematic regions of the country are further analysed in order to identify factors that have the biggest influence on the labour market development in depressed regions of the country. The complex analysis of the problem is finalised in the third working section of the dissertation which contains justification of the solutions for the labour market development in the depressed regions. Synergy effects of complex application of such solutions would ensure better results of the socio-economic development in the depressed regions and, at the same time, in the whole country... [to full text]

Systematic analysis of the labour market in depressed regions of the country and justification of complex measures for the development thereof. / Remiantis sistemine depresinių šalies regionų analize, pagrįstas šių regionų darbo rinkos plėtojimo priemonių kompleksas.

In phylogenetic analysis, an important issue is to construct the confidence region for gene trees from DNA sequences. Usually estimation of the trees is the initial step. Maximum likelihood methods are widely applied but few tests are based on distance methods. In this thesis, we propose a new test based on balanced minimum evolution. We first examine the normality assumption of pairwise distance estimates under various model misspeci cations and also examine their variances, MSEs and squared biases. Then we compare the BME method with the WLS method in true tree reconstruction under different variance structures and model pairs. Finally, we develop a new test for finding a confidence region for the tree based on the BME method and demonstrate its effectiveness through simulation.

In 1997, Xian-Jin Li gave an equivalence to the classical Riemann hypothesis, now referred to as Li's criterion, in terms of the non-negativity of a particular infinite sequence of real numbers. We formulate the analogue of Li's criterion as an equivalence for the generalized quasi-Riemann hypothesis for functions in an extension of the Selberg class, and give arithmetic formulae for the corresponding Li coefficients in terms of parameters of the function in question. Moreover, we give explicit non-negative bounds for certain sums of special values of polygamma functions, involved in the arithmetic formulae for these Li coefficients, for a wide class of functions. Finally, we discuss an existing result on correspondences between zero-free regions and the non-negativity of the real parts of finitely many Li coefficients. This discussion involves identifying some errors in the original source work which seem to render one of its theorems conjectural. Under an appropriate conjecture, we give a generalization of the result in question to the case of Li coefficients corresponding to the generalized quasi-Riemann hypothesis. We also give a substantial discussion of research on Li's criterion since its inception, and some additional new supplementary results, in the first chapter. / Thesis (Ph.D, Mathematics & Statistics) -- Queen's University, 2012-07-31 13:14:03.414

Human Immunodeficiency Virus type I genome consists of two identical RNA molecules that are non-covalently linked to form a dimer. HIV-1 immature and mature genomic RNA (gRNA) dimers were found in protease defective (PR -) and wild type virions, respectively, and the 5'untranslated region (5' UTR) was shown to play key roles during the genome dimerization process; but the dimerization mechanism still remains to be clarified My research project is to characterize the dimerization process and the role of 5' UTR in genome dimerization in virions produced by tissue culture cells. I'll firstly show the dimer maturation processes of HIV-1 gRNA isolated from newly released to grown-up (≥10h old) wild type, PR-, and SL1 defective (DeltaIDS) virions respectively. The results showed that HIV-1 gRNA dimer maturation process was protease-dependent and involved multiple steps: from low to high dimerization level and dimer thermostability, and from low dimer mobility to intermediate and high mobility. PR- virions did not freeze gRNA conformation in the primordial nascent state and gRNA changed from monomeric in newly released virions to half dimeric in grown-up virions, which showed that genome was packaged in the form of monomeric RNA or fragile dimers, more thermolabile than immature dimers in grown-up PR- virions. DeltaDIS inhibited gRNA dimerization by about 50% in newly released virions, though grown-up DeltaDIS gRNA was fully dimeric, which indicated that the DIS played the initiation role in gRNA dimerization in HIV-1 virions. The gRNA dimerization rate in PR- or DeltaDIS virions was much slower than that in wild type virions. These results show for the first time the whole process of dimer maturation after virion release, the gRNA conformation rearrangement in PR- virions, and the initiation role of the DIS in HIV-1 virions. Next, I'll provide a rather systematic search for the contribution of different regions in 5' UTR to HIV-1 gRNA dimerization by studying selected mutations singly or together with defective SL1. The results showed that the 5'trans-activation response element (5'TAR) was directly involved in gRNA dimerization, and a long distance base-pairing interaction between a sequence in U5 region (nts105-1l5) and another around the initiation codon of the gag gene (nts334-344) was structurally contributive to gRNA dimerization. Deletions of sequences around the 3'end of Primer Binding Site (PBS) stem-loop moderately decreased gRNA dimerization level. Other sequences in 5' UTR except DIS/SL1, which was previously known to play important roles, didn't show any systematic role. Here the results suggested that the absence of inhibition on gRNA dimerization level with defective DIS might be the compensation of the direct role of 5'TAR; and wild type-like dimerization level of DeltaTAR must be the direct contribution of the DIS.