Statistička zavisnost sekundarne strukture proteina od frekvencije digrama aminokiselina

The statistical dependence of protein secondary structure on amino acid bigram frequencies was studied. Proteins in the PDBSELECT subset of the Protein Data Bank database were investigated. Protein secondary structures were determined using DSSP software. The conditional probabilities of protein secondary structures were calculated and presented. The results on bigrams show the frequencies of all the possible bigrams in all secondary structure types. These results elucidate some factors important for the prediction of the secondary structures of proteins based on the amino acid sequence. © 2017, CI and CEQ. All rights reserved.U radu je opisana statistička zavisnost sekundarne strukture proteina od bigrama aminokiselina. Istraživanje je urađeno na proteinima koji se nalaze u podskupu PDBSELECT baze podataka o proteinima Protein Data Bank (PDB). Sekundarne strukture proteina su određene primenom programa DSSP. Izračunate su i prikazane uslovne verovatnoće pojavljivanja različitih sekundarnih struktura. Rezultati za bigrame su prikazani za sve tipove sekundarnih struktura. Rezultati ukazuju na faktore koji su značajni za predviđanje sekundarne strukture proteina koje je zasnovano na redosledu aminokiselina u proteinu

Urban Growth and Urbanization of Sofiа, Belgrade and Rome: the Interaction between Urban Planning and the Market

The paper explores the problems of sustainable and resilient development of the cities in Eastern and South-east Europe on the examples of Sofia, Belgrade and Rome and their urban regions. The research draws comparisons to the forms, patterns and mechanisms of their development.Editors: Atanas Kovachev, Aleksandar D Slaev, Diliana Daskalov

Megaprojects as an instrument of urban planning and development: example of Belgrade Waterfront

The research analyzed the theoretical and methodological background of urban megaprojects (UMPs) as instrument of urban planning and development, with specific reference to the Belgrade Waterfront Project (BWP). In analysis we combined a contextually appropriate ap-proach, some elements of the phronetic planning approach and the benchmarking analysis of megaproject planning and development. BWP induced a change of the institutional framework (introduction of specific legal and policy instruments), as a key source of future changes in the metropolitan tissue. Preliminary impact assessment of the BWP indicates: slow development & economic effects, low transparency, social inequalities, marginal social mobilization and weak networks between the key actors, public funds overuse, impact on law-making, displacement impacts, high public financial risk, deep urban transformations, environmental impacts, medium-technological modernization, etc. This research highlights the differences in the political, institutional, social and economic environment that shape the BWP. It provides recommendations for future research and application, improvement of planning approach and continuing in-depth analysis for managing the undesirable consequences of the UMPs, including the determination of the interplay between different pools of power.Slična verzija rada bila je prezentovana na konferenciji UNESCO (2016) pod istim naslovom Megaprojects as an Instrument of Urban Planning and Development: Example of Belgrade Waterfront Project, in UNESCO Chair in Technologies for Development: From Innovation to Social Impact, UNESCO Chair Conference on Technologies for Development: From Innovation to Social Impact, 2-4 May 2016, Ecole Polytechnique Federale de Lausanne - EPFL, Cooperation & Development Center - CODEV, Lausanne, Switzerland, pp.104, http://cooperation.epfl.ch/files/content/sites/cooperation/files/Tech4Dev%202016/Tech4Dev2016_Brochure_14Apr_WebVersion.pdfEditors: Silvia Hostettler, Samira Najih Besson, Jean-Claude Bola

Logic of the Ontological Argument

In his ontological argument G\"{o}del says nothing about its underlying logic. The argument is modal and at least of second-order and since S5 axiom is used so it is widely accepted that the logic of the argument is the S5 second-order modal logic. However, there is a step in the proof in which G\"{o}del applies the necessitation rule on the assumptions of the argument. This is repeated by all of his followers. This application of the necessitation rule can seriously harm the consequence relation of the logic of the ontological argument. It seems that the only way to preserve the modal logic S5 for the ontological argument is to assume some of its axioms in the necessitated form

Nowe podejście do wyznaczania najważniejszych elementów systemu oraz poprawy niezawodności systemu w warunkach ograniczonego budżetu

W złożonych systemach, w których koszty poprawy niezawodności poszczególnych elementów są znane, często ogranicza się budżet przeznaczony na podnoszenie ogólnej niezawodności systemu. W takich przypadkach konieczna jest maksymalizacja niezawodności systemu przy jednoczesnym utrzymaniu kosztów na poziomie minimum. Powszechnie znane metody rozwiązywania powyższego problemu opierają się na wyznaczaniu ważności kosztów, co wymaga określenia rang elementów składowych systemu, a w dalszej kolejności wyodrębnienia pewnej liczby najważniejszych elementów pierwszorzędnej rangi. W niniejszej pracy zaproponowano nowe podejście do określania najważniejszych komponentów systemu w oparciu o problem maksymalnego pokrycia w granicach budżetu (budgeted maximum coverage problem); podejście wdrażano z wykorzystaniem wcześniej znanych minimalnych przekrojów niezdatności. Optymalizacja proponowanego modelu matematycznego, pozwoliła na jednoczesne wyznaczenie wszystkich najważniejszych elementów, dla których łączne wydatki na utrzymanie ruchu nie przekraczały całkowitego ograniczonego budżetu. Nowe podejście zostało przebadane w serii eksperymentów przeprowadzonych na zbiorze przykładów testowych, za które posłużyły wzorcowe drzewa błędów. Wyniki badań porównano z wynikami uzyskanymi za pomocą dwóch miar ważności kosztów – miary ważności opartej na kosztach oraz miary ważności opartej na opłacalności. W większości przypadków, proponowany model dawał lepsze wyniki niż pomiary ważności kosztów.Importance measures are used for indexing system components due to their impact on the system’s overall reliability. In order to identify the specific number of the most critical components, first-ranked components are singled out as the most important ones. However, importance measures consider only the influence of individual components and they are not applicable to combinations or groups of components. This common feature of importance measures is referred to in literature as one of still open issues. This paper proposes a new approach for determining the most important system components, where a whole set of components are determined simultaneously taking into account their interdependence. In systems with a large number of interdependent components, the number of the most important components which should be prevented is often limited due to the available budget. Using pre-known minimal cut sets, a mathematical model based on the Budgeted Maximum Coverage Problem is proposed. By its optimization, the simultaneous determination of all of the most important components whose total expenses do not exceed the limited overall budget is achieved. The new approach was tested by a series of experiments conducted over a set of test examples. The results of the experiments were compared with the results obtained using two commonly used cost importance measures

A framework for additional server activation

This paper assesses the performance of the queuing system with several fixed and additional multitask servers. The additional server serves customers in the case of necessity to avoid congestion and decrease the number of impatient customers. An additional server will be activated whenever the length of queue becomes greater than or equal to user defined size i.e. threshold value. Also, this server will be switched off when the length of queue falls below user defined size, but ongoing service has to be finished.The main issue is to decide when and how long the additional server would work with customers. This paper proposes a methodology to choose the best activation rule for the work of an additional server, based on the performance evaluation of queuing system. The Petri nets (PN) simulation is used to calculate the performance measures. Relative efficiency evaluation of different activation rules is carried out by data envelopment analysis (DEA). The methodology is applied on real-life data collected from a postal office

Radiation Chemistry of Overirradiated Aqueous Solutions of Hydrogen Cyanide and Ammonium Cyanide

The radiolysis of aqueous solutions (O2-free) of HCN and NH4CN was examined at very large doses of 60Co gamma radiation (up to 230 Mrad). In this dose range the cyanide initially present (0.12 M) is decomposed and only its radiolytic products participate in the radiation-induced chemical process. It has been found that the weight of the dry residue containing the mixture of nonvolatile radiolytic products increases as doses increase up to 40 Mrad (up to about 4 g/l), but with further dose increases remains practically unchanged (NH4CN) or decreases slightly (HCN). Carboxylic and amino acids are present in overirradiated samples. At increasing doses their concentrations decrease, with the exception of oxalic and malonic acids, which are continually produced and accumulate. This is also the case with the abundant NH3 and CO2, as well as with several other products that were generated at lower radiation-chemical yields. The molecular weights of the radiolytic products are up to 20,000 daltons throughout the dose range studied. Their amounts gradually change with increasing doses above 30 Mrad: The compounds with Mw between 2,000 and 6,000 daltons become more abundant, while the amounts of polymers with Mw between 6,000 and 20,000 decrease. The relevance of these findings for studies of chemical evolution is considered

Bullwhip dependency of participants' risk preferences in the supply chain

This paper examines the causes of risk preferences, as one of the personality traits, of the participants in the supply chain on inventory and backorder costs. Based on test results the participants are divided into two groups: risk - seeking and risk - averse. Two teams are formed who simulated a beer game. It is shown that there are differences in costs between these teams

Dynamic QoS Management for a Flexible 5G/6G Network Core: A Step toward a Higher Programmability

The academic and professional community has recently started to develop the concept of 6G networks. The scientists have defined key performance indicators and pursued large-scale automation, ambient sensing intelligence, and pervasive artificial intelligence. They put great efforts into implementing new network access and edge computing solutions. However, further progress depends on developing a more flexible core infrastructure according to more complex QoS requirements. Our research aims to provide 5G/6G core flexibility by customizing and optimizing network slices and introducing a higher level of programmability. We bind similar services in a group, manage them as a single slice, and enable a higher level of programmability as a prerequisite for dynamic QoS. The current 5G solutions primarily use predefined queues, so we have developed highly flexible, dynamic queue management software and moved it entirely to the application layer (reducing dependence on the physical network infrastructure). Further, we have emulated a testbed environment as realistically as possible to verify the proposed model capabilities. Obtained results confirm the validity of the proposed dynamic QoS management model for configuring queues’ parameters according to the service management requirements. Moreover, the proposed solution can also be applied efficiently to 5G core networks to resolve complex service requirements