1,072 research outputs found
CERTAIN COVERINGS OF FINITE HOMOCYCLIC ABELIAN GROUPS
Let G be a finite Abelian group written additively which is the n-fold direct sum of
cyclic groups of order k. Denote A the union of these direct summands of G. Let r(k, n) be
the minimum of the cardinality of subsets
ON THE ACCURACY OF MOBILITY MODELLING IN WIRELESS NETWORKS
In a wireless mobile network, two major
problems arise: poor performance of the wireless layer and effect of
user mobility. The problems related to limited available radio bandwidth and
radio channel errors seem to be solved by CDMA technique applied in 3G
mobile systems. The bandwidth that is provided by CDMA air interface is
enough for present mobile multimedia applications. However such applications
are sensitive to the degradation of QoS parameters. Graceful degradation
could happen when too many mobiles arrive to the same radio cell. To avoid
such situations the Call Admission Control (CAC) has to limit the number of
newly accepted connections. Terminal mobility causes problems in call
admission control because the number of active mobile terminals in a cell is
a random variable. In this paper we introduce a new method to predict the
number of terminals in each cell. Based on this information a more effective
CAC algorithm can be applied in order to ensure user´s satisfaction
A rĂ©z-alumĂnium fĂ©mpár korrĂłziĂłs sajátosságai = Corrosion properties of the copper-tin metal couple
Munkánk során megállapĂtottuk, hogy: - Az alumĂniummal elektromosan vezetĹ‘ kapcsolatban lĂ©vĹ‘ rĂ©z sĂşlyos lyukkorrĂłziĂłs károkat okozhat levegĹ‘n lĂ©vĹ‘, klorid-ionokat tartalmazĂł oldatokban. Ilyen körĂĽlmĂ©nyek között, egyforma nagyságĂş felĂĽlettel rendelkezĹ‘ alumĂniumot is rezet összekapcsolva a közös nyitott áramköri potenciál az alumĂnium lyukkorrĂłziĂłs tartományába esik. - A rĂ©z-ionok hatása hasonlĂł, mivel cementáciĂłval leválnak az alumĂnium felĂĽletĂ©re. - Az oldatok oxigĂ©nmentesĂtĂ©se csökkenti a lyukkorrĂłziĂłs veszĂ©lyt. - Klorid-ion mentes közegben rĂ©z hatására nem tapasztalhatĂł pitting korrĂłziĂł. Ilyen körĂĽlmĂ©nyek között a rĂ©z kevĂ©sbĂ© jelent kockázatot. - Az alumĂnium felĂĽletĂ©n keletkezĹ‘ passzĂválĂł oxidrĂ©teg növelĂ©se - pl. forrĂłvizes kezelĂ©ssel - vĂ©delmet nyĂşjthat a rĂ©z Ă©s a klorid egyĂĽttes hatására jelentkezĹ‘ lyukkorrĂłziĂł ellen. | It has been found that: - The presence of copper galvanically connected to aluminium can result in vigorous pitting corrosion of Al in aerated chloride containing solutions. In such circumstances the common open circuit potential of a coupled Al and Cu having equal surface area usually falls in the region of pitting corrosion of aluminium. - Copper ions have the same effect since copper atoms can be deposited on the surface of aluminium via cementation. - Deaerated solutions can be more favourable in order to avoid pitting corrosion - In chloride ion free electrolyte there was no sign of pitting corrosion in the presence of copper. - Passivation of aluminium surface in boiling water can provide protection against pitting corrosion induced by copper and chloride
Fémek adszorpciója idegen fémfelületeken (gyakorlati vonatkozások) = Underpotential deposition of metals on foreign metal surfaces (practical aspects)
A fĂ©mfelĂĽletkĂ©mia három terĂĽletĂ©vell foglalkoztunk a pályázat idĹ‘tartama alatt. ElĹ‘ször, az alapvetĹ‘ cĂ©lkűzĂ©ssel, a fĂ©madszorpciĂłval (UPD), a rĂ©nium platinán vĂ©gbemenĹ‘ adszorpciĂłjával, továbbá egyĂĽttműködĂ©sben az adszorbeált fĂ©mekkel mĂłdosĂtott katalizátorokkal, Ă©s vĂ©gĂĽl az adszorbált fĂ©meknek az alapfĂ©m korrĂłziĂłs sajátságaira gyakorolt hatásával (kĂ©t Ă©s többfĂ©mes korrĂłziĂł) foglalkoztunk. Másodszor, összefoglalĂł dolgozatokat tettĂĽnk közzĂ© a katĂłdos korroziĂłvĂ©delem működĂ©sĂ©nek jobb elmĂ©leti megalapozása cĂ©ljábĂłl azĂ©rt, hogy ösztönözzĂĽk az eljárás mĂ©g szĂ©lesebbkörű alkalmazását, kĂĽlönös tekintettel a hazai hidak tovább aligha halogathatĂł katĂłdos korrĂłziĂłvĂ©delmĂ©re. A harmadik, terĂĽlet a fĂ©mkorrĂłziĂł terĂĽletĂ©n elĹ‘fordulĂł katalitikus jelensĂ©gek feltárása Ă©s elmĂ©leti megalapozása. Legfontosabb eredmĂ©nyĂĽnk a vas-cink korrĂłziĂłs cella polaritásának megváltozását Ă©rtelmezĹ‘ elmĂ©leti munkánk, mely szerint a jelensĂ©g oka a cink felĂĽletĂ©n kĂ©pzĹ‘dĹ‘ passziválĂł oxidrĂ©teg katalitikusan aktiválja az oxigĂ©nt Ă©s ez a cink elektrĂłdpotenciáljának pozitĂv irányĂş elmozdulását eredmĂ©nyezi. Ă–sszefoglalását adtuk azoknak a folyamatoknak, amelynek eredmĂ©nyekĂ©ppen a fĂ©mkorrĂłziĂł során a dioxigĂ©n (katalitikusan)aktiválĂłdik. MegállapĂtottuk, hogy levegĹ‘s kloridtartalmu oldatban a rĂ©zzel Ă©rintkezĹ‘ alumĂnium lyukkorrĂłziĂłja azonnal elkezdĹ‘dik, OxigĂ©n távollĂ©tĂ©ben ez folyamat nem olyan erĹ‘teljes. Az alunĂnium passziválĂłdása akadályozza ezt a kĂ©tfĂ©mes korrĂłziĂłt. | Iin the course of the grant three fields of metal surface chemistry has been dealt with. First, it was dealt with the basic programme, with metal adsorption (UPD), adsorption rhenium on platinum, then with preparation of catalysts midified by adsorbed metals, and finally with the influence of adsorbed metals on corrosion behaviour of the substrate metal (bimetallic or multimetallic corrosion). Secondly, review papers were published to make a better foundation for cathodic corrosion protection. Our papers aiming at inciting an even more wide application of the method, regarding the cathodic protection of the bridges which hardly can be delayed further. Third, revelation and theoretical foundation of catalytic phenomena in the field of metal corrosion. The most important result in this field is the theoretical interpretation of polarity reversal of Zn-Fe corrosion cell. This phenomenon is caused by the catalytic activation of oxygen by the passivating oxide layer on zinc surface and this process results in a positive shift of electrode potential of the zinc. It has been found that in aerated chloride ion containing solution, pitting corrosion of an Al/Cu bimetallic system, emerged immediately, while in the absence of oxygen this process was less violent. The processes resulting in (catalytic) activation of dioxygen in metal corrosion have been summarized (calling the attention to the catalytic aspects of cathodic processes of metal corrosion)
PROBLEME DER QUALITĂ„TS KONTROLLE VON ERZEUGNISSEN
PROBLEMS OF PRODUCT QTIALITY CONTROL - Quality control is generaIly
expected to show whether, after testing one or several characteristics, a set of products can be
accepted or not. Acceptance of a shipment may be decided over according to different sampling
plans, of which some. likely to be expedient, will be presented beIow. The so-called acceptance
plan type (Po, PI' co' Cl) underlying decision according to function V(p) (acceptance probability)
will be expounded.
FinaIly, the number of sampIe elements needed for thc given (or assumed) acceptance
plan type (Po' PI. Fo ' 2 1) wiII be determined, provided certain conditions have been met
A versenyképesség növelésének lehetőségei az Észak-magyarországi Régióban = The possibilities of intensifying competitiveness in the Northern-Hungarian region
Az Észak-magyarországi rĂ©giĂł Ă©s kistĂ©rsĂ©gei jellemzĹ‘inek elemzĂ©se alapján meghatároztuk a rĂ©giĂł hátrányos helyzetű kistĂ©rsĂ©geinek felzárkĂłztatását, versenykĂ©pessĂ©gĂ©nek, jövedelemtermelĹ‘ kĂ©pessĂ©gĂ©nek Ă©s foglalkoztatási potenciáljának növelĂ©si lehetĹ‘sĂ©geit. Mintaprogramokat alkottunk, melyek nem csak a kutatási tervben megjelölt kĂ©t kistĂ©rsĂ©gben, hanem az ország más kistĂ©rsĂ©geiben hasznosĂthatĂłk. A versenykĂ©pessĂ©g növelĂ©sĂ©t szolgálĂł lehetĹ‘sĂ©gek, programok: 1) KistĂ©rsĂ©gi központok, a városok Ă©s a telepĂĽlĂ©sek közötti egyĂĽttműködĂ©sek 2) Falugondnoki Ă©s tanyagondnoki szolgáltatás 3) Teleházak 4) Távmunka-ház 5) Szociális zöldenergia program 6) MEGA ZöldsĂ©g program (MEGA = MegĂşjulĂł EnerGiára Alapozott) 7) Zöldenergia TanácsadĂł Szolgálat - ZETA 8) HálĂłzati gazdaság Az 5-7. pontokban felsorolt programok elmĂ©leti megalapozását jelen kutatás szolgálta. A fĹ‘iskola KutatĂł, FejlesztĹ‘ Központja - felhasználva a kutatási eredmĂ©nyeket - rĂ©szletes programokat dolgozott ki, melyek gyakorlati megvalĂłsĂtása (MEGA ZöldsĂ©g program fĹ‘iskolai pilot-projektje, a zöldenergia Ă©s a MEGA ZöldsĂ©g program egyĂĽttes alkalmazása a jelen kutatásban megjelölt kistĂ©rsĂ©gben) elĹ‘kĂ©szĂtĂ©s alatt van. Az eredmĂ©nyek hasznosulásának másik kiemelt terĂĽlete az oktatás (felsĹ‘oktatás, felnĹ‘ttkĂ©pzĂ©s): - kutatási eredmĂ©nyek beĂ©pĂtĂ©se a gazdasági Ă©s vidĂ©kfejlesztĂ©si agrármĂ©rnök BSc, valamint a vidĂ©kfejlesztĂ©si agrármĂ©rnök MSc szakok tantárgyi programjaiba, - kutatási háttĂ©r a hallgatĂłk, oktatĂłk tudományos tevĂ©kenysĂ©gĂ©hez. | Based on the analysis of the characteristics of the North-Hungarian Region and its small regions, the ways of improving the under-developed small regions, the possibilities of increasing their income-producing ability and employment potentials have been defined. Model programmes have been created to be used not only in the indicated two small regions mentioned in the research plan but also in other small regions of the country as well. Model programmes: 1 Cooperation between small region centres, cities and settlements 2 Services of village caretakers and farm caretakers 3 Tele-houses 4 Teleworking house 5 Social green energy programme 6 Renewable Energy Based Vegetable Programme 7 Green Energy Counselling Service 8 Network economy The present research serves as a theoretical basis for the programmes listed in points 5-7. Using the findings, the Research and Development Centre of the College has worked out detailed programmes and has already started their realisation in practice (College pilot project of MEGA Vegetable Programme, the joint application of green energy and the MEGA Vegetable Programme). The other field of utilisation of the findings is education: - Incorporation of the findings in the subject programmes of the Economic and Rural Development Agricultural Engineering BSc and the Rural Development Agricultural Engineering MSc Programmes; - Creation of a suitable background for research activities carried out by the students and teachers
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