Homotopy colimits – comparison lemmas for combinatorial applications

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.We provide a “toolkit” of basic lemmas for the comparison of homotopy types of homotopy colimits of diagrams of spaces over small categories. We show how this toolkit can be used in quite different fields of applications. We demonstrate this with respect to 1. Björner's “Generalized Homotopy Complementation Formula” [5], 2. the topology of toric varieties, 3. the study of homotopy types of arrangements of subspaces, 4. the analysis of homotopy types of subgroup complexes

Adaptive Tuning of Drop-Tail Buffers for Reducing Queueing Delays.

Internet router buffers are used to accommodate packets that arrive in bursts and to maintain high utilization of the egress link. Such buffers can lead to large queueing delays. We propose a simple algorithm, Active Drop-Tail (ADT), which regulates the queue size, based on prevailing traffic conditions, to a minimum size that still allows for a desired (high) level of utilization. Packet level ns2 simulations are provided to show that Adaptive Drop-Tail achieves significantly smaller queues than current approaches at the expense of 1-2% of the link utilization

Graft-take Success in Walnut Under Controlled Conditions and Plant Development in the Nursery

The production of walnut nursery plants is a complex process, being dependent upon a range of factors that affect graft-take success and behaviour of walnut plants in the nursery. The experiment included two parts. Three different treatments were used in the heated room under controlled air temperature and humidity conditions: Treatment 1-grafting without paraffin treatment of the scion and graft union, coupled with covering the graft with sawdust up to the top of the scion; Treatment 2-grafting involving paraffin treatment of the scion and graft union, coupled with covering the graft with sawdust up to the top of the scion; and Treatment 3-grafting involving paraffin treatment of the scion and graft union, coupled with covering the graft with both sawdust up to the top of the scion and polyethylene foil. The treatments were evaluated for their effect on graft-take success. Graft planting in the nursery was followed by two treatments: treatment without foliar fertilisation and treatment with foliar fertilisation. Under controlled conditions, treatment 3 induced a higher graft-take success as compared to the other two treatments, whereas foliar fertilisation in the nursery had a positive effect on the survival, production of class 1 plants and vegetative growth of walnut plants

Ispitivanja urodinamskih disfunkcija kod bolesnika sa multiplom sklerozom

Background/Aim. Multiple sclerosis (MS) is a chronic autoimmune inflammatory disorder of the unknown origin leading to multifocal demyelization, axonal damage and the loss of the nervous tissue in various parts of the central nervous system. Most MS patients have decreased functionality of the bladder leading to various dysuria disorders during the course of the illness. However, in 2% of the cases dysuric problems are the first symptoms of the disease. Urodynamic testing could help to diagnose functional disorders of the lower urinary tract, which might not be otherwise possible by performing the standard invasive procedures or noninvasive scans, such us ultrasound, computed tomography or functional magnetic resonance imaging (fMRI). Methods. Urodynamic testing - cystometry with electromyographic (EMG) potentials from the external anal sphincter (EAS), was performed in 34 patients (25 female and 9 male patients). Those patients fulfilled Mc Donald's multiple sclerosis criteria. The urodynamic values were compared to neurological signs and the present disease symptoms. Results. The MS patients with (27) and without (7) miction problems were tested. Detrusor hyperreflexia is the most common finding, present in 58.8% of the cases. More than a half of the patients have detrusor sphincter dissynergia. Conclusions. Urodynamic testing helps us to determine neurological disorders characteristics and to prepare an appropriate treatment plan. During the course of the disease different urodynamic disfunctions may occur as well as changes in the urinating functionality. The rationale for urodynamic testing in patients suffering from MS before any other treatment procedure is to confirm the diagnosis of dysuric disorders and to secure appropriate treatment.Uvod/Cilj. Multipla skleroza (MS) je hronično zapaljensko autoimuno oboljenje nepoznate etiologije koje dovodi do multifokalne demijelinizacije, oštećenja aksona i gubitka nervnog tkiva u različitim delovima centralnog nervnog sistema. Većina bolesnika sa multiplom sklerozom ima i poremećenu funkciju mokraćne bešike koja dovodi do različitih dizuričnih smetnji tokom trajanja bolesti. Samo kod 2% bolesnika ove smetnje su prvi simptom bolesti. Urodinamsko ispitivanje omogućava nam da postavimo dijagnozu funkcionalnih poremećaja donjeg urinarnog trakta, što uobičajenim invazivnim procedurama ili neinvazivnim snimanjima (ultrazvuk, kompjuterizovana tomografija ili funkcionalna magnetna rezonanca) često nije moguće ustanoviti. Metode. Urodinamsko ispitivanje - cistometrija i registrovanje elektromiografskih (EMG) potencijala sa spoljašnjeg analnog sfinktera (SAS) urađeno je kod 34 bolesnika (25 žena i 9 muškaraca), koji ispunjavaju Mc Donaldove dijagnostičke kriterijume za multiplu sklerozu. Dobijene vrednosti su upoređivane sa neurološkom simptomatologijom i znacima bolesti. Rezultati. Ispitivani su bolesnici sa (n = 27) i bez (n = 7) mikcionih tegoba. Hiperrefleksija detrusor bila je najčešći nalaz, prisutan čak kod 58,8% bolesnika. Više od polovine ovih bolesnika imalo je detrusor-sfinkter disinergiju. Zaključak. Urodinamsko ispitivanje može pomoći da se utvrde postojeći neurourološki poremećaji i na osnovu njih planira sprovođenje odgovarajućeg terapijskog plana. Tokom trajanja bolesti mogu se ustanoviti različiti oblici urodinamskih nalaza disfunkcije, kao i promena funkcije mokrenja. Razlog za sprovođenje urodinamskog ispitivanja kod bolesnika sa MS pre svake terapije bio bi postavljanje jasne dijagnoze dizuričnih poremećaja koja bliže određuje pravilnu i adekvatnu terapiju

The impact of global capital markets on the capital market in Serbia

Doktorska disertacija “Uticaj svjetskog tržišta kapitala na tržište kapitala u Srbiji” bavi se istraživanjem uticaja svjetskog tržišta kapitala na srpsko tržište kapitala u periodu od 2000- 2015. godine. Uporedo sa ponovnim razvojem trgovine akcijama u Srbiji od 2001. godine, odvijao se i proces tranzicije srpskog tržišta kapitala, prije svega kroz proces reformi regulative, kao i kroz reformu institucija i pojavu novih tržišnih učesnika. Uticaj globalnog tržišta kapitala se ogledao u sprovođenju svih ovih reformi, koje su zaokružile pravni okvir za funkcionisanje srpskog tržišta kapitala u skladu sa svjetskim standarima, kao i kroz prisustvo stranih portfolio investitora, prije svih stranih investicionih fondova, koji su u niskom nivou razvijenosti srpskog tržišta kapitala vidjeli svoju šansu za visoke profitne stope. U 2008. godini, globalno tržište kapitala je bilo pogođeno efektima hipotekarne krize u Sjedinjenim Američkim Državama, koji su potresli čitav svijet, uključujući i Srbiju. Međutim, izuzetno visoke stope rasta berzanskih cijena u Srbiji u prethodnom periodu, dovele su do formiranja nezavisnog berzanskog balona u Srbiji, koji je već počeo svoj silazni trend prije izbijanja svjetske finanisjske krize. Pad vrijednosti indeksa Beogradske berze od 90%, predstavljao je jedan od najvećih gubitaka na globalnom tržištu kapitala. Upravo činjenica da je pad berzanskih cijena počeo prije pojave globalne finansijske krize, a da su ga njeni efekti, kroz povlačenje stranih investitora sa Beogradske berze, dodatno intenzivirali, predstavlja objašnjenje dimenzija berzanskog kolapsa u Srbiji i uticaja svjetskog tržišta kapitala.Doctoral dissertation “The Impact of Global Capital Markets on the Capital Market in Serbia” analyse the impact of the global capital market on Serbian capital market between 2000 and 2015. Simultaneously with the renewed development of stock market in Serbia since 2001, Serbian capital market has also been in the process of transition, before all through the process of regulation reforms, as well as through reforms of institutions and introduction of new participants on the market. The influence of the global capital market was seen in implementation of all these reforms, which completed the legal framework for operation of Serbian capital market in coherence with world standards, as well as through the presence of foreign portfolio investors, above all foreign investment funds, who saw their chance for high profit margins in the low level of development of Serbian capital market. In 2008, the global capital market was hit by the effects of the Subprime crisis in the United States of America, which shook the whole world, including Serbia. However, extremely high increase of stock market prices in Serbia in the previous period created an independent stock market bubble in Serbia, which had already started its decline before the onset of the global financial crisis. The drop in the value of Belgrade Stock Exchange indexes of 90% represented one of the biggest losses at the global capital market during 2007-2009 period

Combines Work Quality in Maize Silage Production

The paper presents testing results of three silage combines employed in maize silage preparation in Toplica region. It is focused on determination of technical working parameters of tested machines. Achieved results verified the superiority of silage combine John Deere 5820, which produced the chopped mass having particle lengths of the smallest deviation with respect to the preset cutting length. In this case, the average length of chopped mass was 9.9 mm, having 69 % mass in the range up to 8 mm. The other two silage combines produced lower mass percentage of this fraction and larger variations of particle lengths with respect to the preset length. Minimum mass flow rate was evidenced for the silage combine Fortschrit E-286: 7.3 kg s-1 (26.3 t h-1) and the surface productivity of 0.83 ha h-1, at the average speed of 4.0 km h-1. Maximum production rate was achieved with silage combine John Deere 5820: 10.9 kg s-1 (39.1 t h-1) at average working velocity of 4.7 km h-1 and surface efficiency of 1.21 ha h-1

The nutritive value of poultry diets containing sunflower meal supplemented by enzymes

The international limitations imposed on the utilization of meat and bone meals in animal diets, together with the increasing demand for soybean meal, create a necessity to search for other protein sources to economically balance compound feeds. In this regard it is important to note that sunflower is the best adapted high-protein crop available in some European regions and that is useful to use it in poultry farming as the replacement of other protein sources. Protein and many other nutrients are “imprisoned” to variable degrees, inside sunflower meal fibrous structures, and remain less available for digestion by the poultry’s own proteases and other endogenous enzymes. Added exogenous enzymes (phytase, hemicellulase, cellulase, carbohydrase, protease, etc.) offer a number of creative possibilities for breakdown and “liberation” of these nutrients, their easier digestion and absorption, and thus development of new nutritional standards and new diets formulation. Supplementation of poultry diets containing sunflower meal by different enzymes increasingly contribute to sustainable poultry farming by enhancing production efficiency, increasing the effectiveness of nutrient utilization and upgrading in environmental protection. [Projekat Ministarstva nauke Republike Srbije, br. III46012

Performance Analysis of One Model of Communication and Information System in Military Operation

This paper presents a model of communication and information system in military operations. Here OPNET MODELER simulation package is applied because it is suitable for network modelling, topology and capacity planning. Simulation of different types of IP traffic and monitor their performance to optimise the functionality of network elements, management performance network applications, and as well as in research and development of new network technologies. Application of the method of mass service are determined by the capacity needed for voice transmission on the links in the model and using the OPNET MODELER simulation program are analysed performance modeled communication information system in data transmission. The results of the simulation are presented through target the service settings: workload links communication and information system, e-mail download response time, http page download response time and packet loss in data transfer. The aim of the research has shown that modeled communication information system with defined elements (nodes), the capacity of links (according to the specification of telecommunication devices) and defined traffic can respond to the requirements of command forces in the military operation in terms of telecommunication service. The results of the analysed service target parameters show that modeled communication and information system provides an efficient flow of information and the tra nsfer of voice and IP data for the needs of command and control in military operations