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Search Results: 1 - 10 of 594072 matches for " Ján Pekár "
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Estimating Flash Flood Peak Discharge in Gidra and Parná Basin: Case Study for the 7-8 June 2011 Flood
Pavla Pekárová, Ale Svoboda, Pavol Miklánek, Peter koda, Dana Halmová, Ján Pekár
Journal of Hydrology and Hydromechanics , 2012, DOI: 10.2478/v10098-012-0018-z
Abstract: We analyzed the runoff and its temporal distribution during the catastrophic flood events on river Gidra (32.9 km2) and Parná (37.86 km2) of the 7th June 2011. The catchments are located in the Small Carpathian Mountains, western Slovakia. Direct measurements and evaluation of the peak discharge values after such extreme events are emphasized in the paper including exceedance probabilities of peak flows and of their causal flash rainfall events. In the second part of the paper, plausible modeling mode is presented, using the NLC (Non Linear Cascade) rainfall-runoff model. Several hypothetical extreme flood events were simulated by the NLC model for both rivers. Also the flood runoff volumes are evaluated as basic information on the natural or artificial catchment storage.
Prediction of Water Quality in the Danube River Under extreme Hydrological and Temperature Conditions
Pavla Pekárová , Milan Onderka , Ján Pekár , Peter Ron ák , Pavol Miklánek
Journal of Hydrology and Hydromechanics , 2009, DOI: 10.2478/v10098-009-0001-5
Abstract: One of the requirements imposed by the Water Framework Directive (WFD, 2000/60/EC) is to analyze and predict how quality of surface waters will evolve in the future. In assessing the development of a stream's pollution one must consider all sources of pollution and understand how water quality evolves over time. Flow and water temperature regime of a stream or river are the main factors controlling the extent to which deterioration of a stream's water quality can propagate under constant input from pollution sources. In addition, there is ever increasing public concern about the state of the aquatic environment. Decision makers and scientists involved in water management call for studies proposing simulation models of water quality under extreme natural hydrologic and climatic scenarios. Also, human impact on water resources remain an issue for discussion, especially when it comes to sustainability of water resources with respect to water quality and ecosystem health. In the present study we investigate the long-term trends in water quality variables of the Danube River at Bratislava, Slovakia (Chl-a, Ca, EC, SO2-, Cl-, O2, BOD5, N-tot, PO4-P, NO3-N, NO2-N, etc.), for the period 1991-2005. Several SARIMA models were tested for the long-term prediction of selected pollutant concentrations under various flow and water temperature conditions. In order to create scenarios of selected water quality variables with prediction for 12 months ahead, three types of possible hydrologic and water temperature conditions were defined: i) average conditions - median flows and water temperature; ii) low flows and high water temperature; and iii) high flows and low water temperature. These conditions were derived for each month using daily observations of water temperature and daily discharge readings taken in the Danube at Bratislava over the period 1931-2005 in the form of percentiles (1th-percentile, median, 99th-percentile). Once having derived these extreme-case scenarios, we used selected Box-Jenkins models (with two regressors - discharge and water temperature) to simulate the extreme monthly water quality variables. The impact of natural and man-made changes in a stream's hydrology on water quality can be readily well simulated by means of autoregressive models.
Multi-Stage Transportation Problem With Capacity Limit
I. Brezina,Z. ?i?ková,J. Pekár,M. Reiff
International Journal of Lean Thinking , 2010,
Abstract: The classical transportation problem can be applied in a more general way in practice. Related problems as Multi-commodity transportation problem, Transportation problems with different kind of vehicles, Multi-stage transportation problems, Transportation problem with capacity limit is an extension of the classical transportation problem considering the additional special condition. For solving such problems many optimization techniques (dynamic programming, linear programming, special algorithms for transportation problem etc.) and heuristics approaches (e.g. evolutionary techniques) were developed. This article considers Multi-stage transportation problem with capacity limit that reflects limits of transported materials (commodity) quantity. Discussed issues are: theoretical base, problem formulation as way as new proposed algorithm for that problem.
New agnostina (Trilobita) from the Llanvirn (Ordovician) of Spain
Rábano, I.,Pek, H.,Vaněk, J.
Estudios Geologicos , 1985,
Abstract: The agnostids from the Lower Llanvirn shales of the Southern Central-Iberian Zone (Mounts of Toledo, Villuercas and Almadén district) are described. Seven localities are new for Ordovician agnostids and two are revised. Three new species, belonging to the genera Geragnostella and Geragnostus, are described: Geragnostella gilcidae n. sp., Geragnostus hispanicus n. sp. and Geragnostus ninhursagae n. sp. The new names Geragnostus pilleti nom. nov. and Geragnostus abdullaevi nom. nov. are proposed to rename, respectively, the species G. howelli PILLET, 1978 and G. elongatus ABDULLAEV, 1972, regarded herein as junior objective homonyms of other previously defined species. Se estudian los trilobites agnóstidos procedentes de nueve localidades, siete de ellas nuevas para estas faunas, situadas en las pizarras del Llanvirn inferior de la parte meridional de la Zona Centroibérica (Montes de Toledo, Villuercas y región de Almadén). Se determina la presencia de los géneros Geragnostella y Geragnostus, y se describen tres nuevas especies: Geragnostella gilcidae n. sp., Geragnostus hispanicus n. sp. y Geragnostus ninhursagae n. sp. Se proponen también los nuevos nombres Geragnostus pilleti nom. nov. y Geragnostus abdullaevi nom. nov. para designar, respectivamente, las especies G. howelli PILLET, 1978, y G. elongatus ABDULLAEV, 1972, consideradas ambas homónimos objetivos primarios de otras especies definidas con anterioridad.
Comparison of the Subgross Distribution of the Lesions in Invasive Ductal and Lobular Carcinomas of the Breast: A Large-Format Histology Study
Syster Hofmeyer,Gyula Pekár,Mária Gere,Miklós Tarján,Dan Hellberg,Tibor Tot
International Journal of Breast Cancer , 2012, DOI: 10.1155/2012/436141
Abstract: To compare the lesion distribution and the extent of the disease in ductal and lobular carcinomas of the breast, we studied 586 ductal and 133 lobular consecutive cancers. All cases were documented on large-format histology slides. The invasive component of ductal carcinomas was unifocal in 63.3% (371/586), multifocal in 35.5% (208/586), and diffuse in 1.2% (7/586) of the cases. The corresponding figures in the lobular group were 27.8% (37/133), 45.9% (61/586), and 26.3% (35/133), respectively. When the distribution of the in situ and invasive component in the same tumors was combined to give an aggregate pattern, the ductal carcinomas were unifocal in 41.6% (244/586), multifocal in 31.6% (185/586), and diffuse in 26.8% (157/586) of the cases. The corresponding figures in the lobular category were 15.0% (20/133), 54.2% (72/133), and 30.8% (41/133), respectively. Ductal cancers were extensive in 45.7% (268/586), lobular in 65.4% (87/133) of the cases. All these differences were statistically highly significant ( ). While the histological tumor type itself (ductal versus lobular) did not influence the lymph node status, multifocal and diffuse distribution of the lesions were associated with significantly increased risk of lymph node metastases in both ductal and lobular cancers. 1. Introduction Breast cancer is a heterogeneous disease in which the individual cases deviate from each other in morphology, protein expression, molecular phenotype, genetic characteristics, and prognosis. Breast carcinomas of “special-types” have been delineated based on their microscopical characteristics, but the vast majority of tumors belongs to the category of not otherwise specified (NOS) ductal carcinomas. Invasive lobular carcinomas represent the most frequent “special-type” breast carcinoma and comprise 5–15% of all breast cancer cases [1]. In addition both the ductal and the lobular tumors also represent heterogeneous groups of diseases and can be prognostically stratified with grading or delineating distinct histological subtypes. Numerous studies have compared ductal and lobular breast carcinomas using different criteria, and reported more [2, 3] or less favourable [4, 5] outcome in lobular compared to ductal carcinomas, or no significant differences in outcome [6, 7]. On the other hand, studies on subgross morphology (lesion distribution and disease extent) of these tumors are very rare. Tot has previously described the diffuse variant of invasive lobular carcinoma and reported a poorer prognosis when compared to unifocal and multifocal lobular cancers [8]. Foschini
Vaccination ratio of the hospitalized infants
Lale Pulat Seren,Abdülkadir Bozaykut,?lke ?zahi ?pek,R G?nül Sezer
Medical Journal of Bakirk?y , 2006,
Abstract: Objective: The aim of the study was to determine vaccination ratios, to find the reasons of missing vaccination and to inform the parents about the benefits of vaccines. Material and Methods: The present study was performed among hospitalized infants between January 1, 2004 - December 31, 2004. Results: The mean age of 660 infants consisting the study group was 5,3 (1-12) months. The parents were asked if their children was vaccinated with BCG, Diphteria- Pertussis-Tetanos, Polio, Hepatitis B and Measles. It was found that 274 (41,5%) of the infants had been vaccinated with all, 200 (30,3%) of the infants had missing vaccines and remaining 186 (28,2%) infants had never been vaccinated. The reasons for missing or absent vaccination were getting sick in the time of vaccination in 36,2%, the ignorance of the parents in 22,2% and being of low birth weight infant in 12,5% of the infants. Conclusion: We concluded that the vaccination ratios could be increased by informing the parents in our country where the prevalance of the infectious diseases and malnutrition is so high. Moreover, the quality of health services could be raised by using the opportunities for completing the missing vaccines.
Spin state of negative charge-transfer material SrCoO3
J. Kune?,V. K?ápek,N. Parragh,G. Sangiovanni,A. Toschi,A. V. Kozhevnikov
Physics , 2012, DOI: 10.1103/PhysRevLett.109.117206
Abstract: We employ the combination of the density functional and the dynamical mean-field theory (LDA+DMFT) to investigate the electronic structure and magnetic properties of SrCoO3, monocrystal of which were prepared recently. Our calculations lead to a ferromagnetic metal in agreement with experiment. We find that, contrary to some suggestions, the local moment in SrCoO3 does not arise from intermediate spin state, but is a result of coherent superposition of many different atomic states. We discuss how attribution of magnetic response to different atomic states in solids with local moments can be quantified.
Molecular Phenotypes of Unifocal, Multifocal, and Diffuse Invasive Breast Carcinomas
Tibor Tot,Gyula Pekár,Syster Hofmeyer,Maria Gere,Miklós Tarján,Dan Hellberg,David Lindquist
Pathology Research International , 2011, DOI: 10.4061/2011/480960
Abstract: We analyzed the subgross distribution of the invasive component in 875 consecutive cases of breast carcinomas using large-format histology sections and compared the immunophenotype (estrogen and progesterone receptor expression, HER2 overexpression and expression of basal-like markers, CK5/6, CK14, and epidermal growth factor receptor) in unifocal, multifocal, and diffuse tumors. Histology grade and lymph node status were also analyzed. Unifocal invasive carcinomas comprised 58.6% (513/875), multifocal invasive carcinomas 36.5% (319/875), and diffuse invasive carcinomas 4.9% (43/875) of the cases. The proportion of lymph node-positive cases was significantly higher in multifocal and diffuse carcinomas compared to unifocal cancers, but no other statistically significant differences could be verified between these tumor categories. Histological multifocality and diffuse distribution of the invasive tumor component seem to be negative morphologic prognostic parameters in breast carcinomas, independent of the molecular phenotype.
Differences between Epilepsy Patients Under Politherapy and Epilepsy Patients Under Monotherapy
?zgür B?LG?N TOP?UO?LU,Kadriye A?AN,pek M?D?,Canan AYKUT B?NG?L
Marmara Medical Journal , 2012,
Abstract: Objective: This study aimed to evaluate demographical variables, clinical features, neurological examination and cranial imaging results which cause or determine the necessity for politherapy treatment in epilepsy patients.Patients and Methods: The patient files of 785 epileptic patients were followed by Marmara University Epilepsy Outpatient Clinic were scanned retrospectively and a questionnaire was filled in for each file. Patients were grouped as monotherapy or politherapy, considering the number of antiepileptics they used. The demographical variables, clinical features, neurological examination and imaging results of the two groups were compared. The results were analyzed by Student's-t test and chi-square tests.Results: A history of craniotomy and intracranial tumors is more frequent in politherapy patients. Also, simple partial seizure, convulsive status epilepticus, pathological neurological examination findings, abnormal EEG, cranial imaging (MRI/CT) and SPECT results were found to be higher in politherapy patients.Conclusion: Politherapy is an important step in epilepsy treatment. However, because of drug-drug interactions and drug side effects it is not the first choice. Determining the differences between patients who use politherapy and monotherapy will help recognizing the clinical data which may lead to politherapy need. (Marmara Medical Journal 2012;25:123-7)
Portfolio Selection by Maximizing Omega Function using Differential Evolution  [PDF]
PEKáR Juraj, BREZINA Ivan, ?I?KOVá Zuzana, REIFF Marian
Technology and Investment (TI) , 2013, DOI: 10.4236/ti.2013.41B012
Abstract: Paper presents alternative solution seeking approach for portfolio selection problem with Omega function performance measure which allows determining capital allocation over the number of assets. Omega function computability is diffi-cult due to substandard structures and therefore the use of standard techniques seems to be relatively complicated. Dif-ferential evolution from the group of evolutionary algorithms was selected as an alternative computing procedure. Al-ternative approach is analyzed on the Down Jones Industrial Index data. Presented approach enables to determine good real-time solution and the quality of results is comparable with results obtained by professional software.
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