Search Process and Probabilistic Bifix Approach

An analytical approach to a search process is a mathematical prerequisite for digital synchronization acquisition analysis and optimization. A search is performed for an arbitrary set of sequences within random but not equiprobable L-ary data. This paper derives in detail an expression for probability distribution function, from which other statistical parameters - expected value and variance - can be obtained. The probabilistic nature of (cross-) bifix indicators is shown and application examples are outlined, ranging beyond the usual telecommunication field.Comment: 4 pages, 2 figures, to appear in Proceedings of the 2005 IEEE International Symposium on Information Theory, Adelaide, Australia, September 4-9, 200

User Activity Detection in Massive Random Access: Compressed Sensing vs. Coded Slotted ALOHA

Machine-type communication services in mobile cel- lular systems are currently evolving with an aim to efficiently address a massive-scale user access to the system. One of the key problems in this respect is to efficiently identify active users in order to allocate them resources for the subsequent transmissions. In this paper, we examine two recently suggested approaches for user activity detection: compressed-sensing (CS) and coded slotted ALOHA (CSA), and provide their comparison in terms of performance vs resource utilization. Our preliminary results show that CS-based approach is able to provide the target user activity detection performance with less overall system resource utilization. However, this comes at a price of lower energy- efficiency per user, as compared to CSA-based approach.Comment: Accepted for presentation at IEEE SPAWC 201

Performance analysis of wireless communication system in general fading environment subjected to shadowing and interference

In this paper, performance analysis of wireless communication over α−η−μ fading channels has been investigated. First, analysis has been carried out for the case when communication is subjected to the influence of co-channel interference. Closed-form expressions have been derived for the probability density function and cumulative distribution function of the received signal-to-interference ratio. Outage probability has been obtained for this case, in the function of various values of system parameters, and also for the case when selection diversity has been presented at the reception. Further, simultaneous multipath fading and shadowing occurrence has been analyzed, through deriving novel composite Gamma long-time faded α−η−μ fading distribution. First-order statistical parameters have been obtained in closed form, for this novel composite distribution, and capitalizing on them, standard performance measures have been efficiently evaluated, graphically presented and discussed in the function of system parameters

Timely and Efficient Information Delivery in Real-Time Industrial IoT Networks

Enabling real-time communication in Industrial Internet of Things (IIoT) networks is crucial to support autonomous, self-organized and re-configurable industrial automation for Industry 4.0 and the forthcoming Industry 5.0. In this paper, we consider a SIC-assisted real-time IIoT network, in which sensor nodes generate reports according to an event-generation probability that is specific for the monitored phenomena. The reports are delivered over a block-fading channel to a common Access Point (AP) in slotted ALOHA fashion, which leverages the imbalances in the received powers among the contending users and applies successive interference cancellation (SIC) to decode user packets from the collisions. We provide an extensive analytical treatment of the setup, deriving the Age of Information (AoI), throughput and deadline violation probability, when the AP has access to both the perfect as well as the imperfect channel-state information. We show that adopting SIC improves all the performance parameters with respect to the standard slotted ALOHA, as well as to an age-dependent access method. The analytical results agree with the simulation based ones, demonstrating that investing in the SIC capability at the receiver enables this simple access method to support timely and efficient information delivery in IIoT networks

Performance Analysis of 5G Transmission over Fading Channels with Random IG Distributed LOS Components

Mathematical modelling of the behavior of the radio propagation at mmWave bands is crucial to the development of transmission and reception algorithms of new 5G systems. In this study we will model 5G propagation in nondeterministic line-of-sight (LOS) conditions, when the random nature of LOS component ratio will be observed as Inverse Gamma (IG) distributed process. Closed-form expressions will be presented for the probability density function (PDF) and cumulative distribution function (CDF) of such random process. Further, closed-form expressions will be provided for important performance measures such as level crossing rate (LCR) and average fade duration (AFD). Capitalizing on proposed expressions, LCR and AFD will be discussed in the function of transmission parameters

Quality Red Wines: Changing the Content of Anthocyanins in the Process of Ripening Grapes

The content of anthocyanins in grape affects the color and sensory properties of red wine. This paper deals with the quality of Cabernet Sauvignon wines examining changes in the content of anthocyanins in the process of ripening grapes. The HPLC results show that the skin extracts obtained from the early defoliation plants showed up to 6 % and corresponding wine up to 24 % increase of the content of total anthocyanins as compared to the extracts from the control grape and corresponding wine samples. Partial early defoliation may be an excellent tool for control of anthocyanins in grapes and may be employed as a management practice as parameter for quality of red wines

PERFORMANCE ANALYSIS OF DUAL-BRANCH SELECTION DIVERSITY SYSTEM USING NOVEL MATHEMATICAL APPROACH

In this paper, novel mathematical approach for evaluation of probability density function (PDF) of instantaneous signal-to-interference ratio (SIR) at the receiver output in interference-limited environment is proposed. Dual-branch selection combining (SC) receiver operating over correlated Weibull fading channels applying SIR algorithm is considered. Analytical expression for joint PDF of desired signal and interference at the receiver output is derived and used for evaluation of PDF of instantaneous SIR. The expression for PDF of SIR is used for system performance analysis via outage probability, average bit error probability (ABEP) and average output SIR as system performance measures. Numerical results are graphically presented showing the effects of fading severity, average SIR at the input and level of correlation on the diversity receiver performance. In addition, results obtained for the PDF of instantaneous SIR in this paper, are compared to the results when the PDF of instantaneous SIR is directly calculated

Primena prebiotika MOS-a u ishrani pastrmki

Ispitivan je uticaj manan oligosaharida (MOS) kao aditiva hrane, primenjenog u koncentraciji od 0,2% (O-I grupa riba) i 0,3% (O-II grupa riba) na morfometrijske karakteristike i osnovne proizvodne pokazatelje gajenja kalifornijske pastrmke. Ogled je sproveden na 450 riba podeljenih u tri grupe sa po 150 jedinki u svakoj grupi i trajao je 40 dana. Analizom dobijenih rezultata, ustanovljen je povoljan efekat primenjenog aditiva na morfometrijske pokazatelje tempa rasta riba, kako njihove završne komadne mase i završnih dužinskih mera, tako i njihovog prirasta, ali bez utvrđenih statistički značajnih razlika (p>0,05). Najveću prosečnu telesnu masu i dužinu tela kod ispitavanih grupa, ostvarile su pastrmke O-II grupe (118,49 g i 19,59 cm), zatim pastrmke O-I grupe (118,04 g i 19,58 cm), a najmanju K-grupa riba (115,94 g i 19,56 cm). Dodavanje MOS-a u smeše za ishranu pastrmki je imalo povoljan uticaj (p>0,05) na ostvarivanje niže konverzije hrane (HK) i boljih vrednosti osnovnih proizvodnih pokazatelja: faktora kondicije (FK), koeficijenta proteinske efikasnosti (PER), specifične stope rasta (SGR) i proizvodnog indeksa (PI) u odnosu na ribe K grupe, koje su hranjene smešama bez dodatka mananoligosaharida. Najbolje rezultate su ostvarile ribe O-II grupe, a iskazano u relativnim pokazateljima u odnosu na K grupu riba: bolju konverziju hrane za 5,61%; bolju vrednost iskorišćenja proteina hrane za 5,94%; veću vrednost faktora kondicije za 1,73%; specifične stopa rasta za 2,26% i bolju vrednost proizvodnog indeksa za 8,27%

Model zaštite prirodnih resursa integracijom upravljačkih funkcija ribarskog i lovnog područja

Ribarska i lovna područja u zakonodavnom, organizacionom i funkcionalnom smislu ispoljavaju veliku sličnost, koja proistiće iz zakonskih definicija. Kvalitet upravljanje obnovljivim resursima u oblasti ribarstva i lovstva uslovljen je političko-zakonodavnim, ekonomskim, socijalnim i tehnološko-ekološkim parametrima (kategorijama) određenim širokim spektrom različitih interesa i potreba. Zato je veoma važno odabrati model upravljanja pomenutim prirodnim resursima koji može zadovoljiti više ciljnih grupa, a da pri tome bude efikasan i ekonomičan. Cilj ovog rada je da se na realan i praktičan način prikažu kriterijumi i alternative za poboljšanje upravljačkih funkcija kroz model zaštite prirodnih resursa integracijom upravljačkih funkcija ribarskog i lovnog područja. Kao polazni materijal u ovom radu korišćeni su zakonska i planska dokumenta iz oblasti održivog korišćenja ribljeg fonda i lovstva. Izvršena je višekriterijumska analiza na osnovu kriterijuma PEST analize u odnosu na moguće alternative (posebno ribarsko, posebno lovno, integralno upravljanje ribarsko-lovnim područjem). PEST analiza se zasniva na analizi eksternih uticaja (Političko-zakonodavna, Ekonomska, Sociološka i Tehnološko-ekološka analiza) koji utiču na izbor organizacionog oblika upravljanja ribarskim i lovnim područijima. Kao kontrolni metod korišćen je analitičko hijerarhijski proces (AHP), sa namerom da se utvrdi u kojoj meri eksterni kriterijumi okruženja deluju na izbor ponuđenih alternativa (Saaty, 1980). Prema većini autora u Srbijii postoji potreba integralnog upravljanja vodnim resursima i vodoprivrednim objektima, koja bi kroz adekvatnu pravnu regulativu ostvarila svoj puni tehnološko-tehnički kapacitet, ekonomičnost, efikasnost i efektivnost. Srbija raspolaže velikim brojem reka, prirodnih i veštačkih akumulacija. Integralno upravljanje rečnim slivom pretpostavlja plansko upravljanje i izradu monitoringa baziranih na ekološkim karakteristikama i kontinuiranom praćenju biotičkih i abiotičkih faktora (Simonović i sar., 2005). U Srbiji je ustanovljeno oko 300 lovišta, u kojima su uočeni kao najčešći nedostaci: nedosledna primena i nepoštovanje zakonskih propisa, monopolizam određenih organizacija i interesnih grupa, nizak nivo tehničko-tehnološkog i institucionalnog razvoja, nepostojanje dokumenta strateškog planiranja u lovstvu, nerazvijeni monitoring divljači i njihovih staništa Sa aspekta održivog upravljanja lovnim područjima osnovni ciljevi su: povećanje brojnosti populacije sitne i krupne divljači, poboljšanje polne i starosne strukture populacija, očuvanje retkih i ugroženih vrsta lovne divljači (Medarević i sar., 2008). Radovi i dokumenta, kao i iskustva drugih zemalja upućuju na potrebu objedinjenog upravljanja pomenutim obnovljivim resursima. Može se zaključiti da bi integralno gazdovanje ribarskim i lovnim područjima poboljšalo upravljačke funkcije, smanjilo troškove i povećalo efikasnost poslovanja. Sigurno bi pozitivno uticalo i na socijalni aspekt i promenu svesti u javnosti da ribolov i lov nisu samo socijalna već i značajna privredna kategorija. Integralnim upravljanjem ribarskim i lovnim područjima bio bi olakšan monitoring sa jasnijim i uporedivim rezultatima, a kontrola i korišćenje finansijskih sredstava bila bi neuporedivo bolja i racionalnija. U pogledu funkcionisanja stručnih i čuvarskih službi potrebno je izvršiti detaljnu analizu geografskog rasporeda, veličine i broja lovnih tj. ribolovnih područja, sa ciljem optimizacije upravljanja istim na ekonomskim i ekološkim principima. Potencijalna korist za državu se vidi u smanjenju troškova uprave, pri čemu bi se mogli formirati regionalni centri na nivou jednog ili više područja, a koji bi služili za obuku kadrova, organizaciju monitoringa, reagovanja u akcidentnim situacijama i slično. Pre toga potrebno je zakonsku regulativu, a potom ribarska i lovna područja učiniti međusobno kompatibilnim