OUTAGE PERFORMANCE OF COGNITIVE RF/FSO SYSTEM WITH MRC SCHEME AT THE RECEIVER

The aim of this paper is performance analysis of the hybrid radio frequency (RF)/free-space optical (FSO) system, where the transmission is performed simultaneously over FSO link and spectrum sharing cognitive RF sub-system. The FSO link is affected by Gamma-Gamma atmospheric turbulence, while in spectrum sharing cognitive RF sub-system the peak interference power constraint at the primary user's receiver is considered in Nakagami-m fading environment. Outage probability expressions are provided in the integral form for the case when the maximal ratio combining (MRC) is applied at the destination. The effects of the atmospheric turbulence strength, the number of RF antennas, allowable power and fading severity on the outage performance are observed. Numerical results are presented and verified by Monte Carlo simulations

A Case of Visceral Leishmaniasis in the Northern Adriatic Region

A 33-year-old male patient with fever, splenomegaly, pancytopenia and lymphocytosis was admitted to the Department of Hematology in Rijeka. Laboratory findings, bone marrow aspiration and biopsy excluded hemoblastosis and aplastic anemia. To exclude primary splenic lymphoma we performed splenic aspiration where Leishmania amastigotes were found. No cases of visceral leishmaniasis have been previously described in the Northern Adriatic region. Considering epidemiology, a contraction of the disease in the Velebit mountain range could be possible despite the current non-endemic status of the region

Less Work, Less Respect: Authors' Perceived Importance of Research Contributions and Their Declared Contributions to Research Articles

BACKGROUND: Attitudes towards authorship are connected with authors' research experience and with knowledge of authorship criteria of International Committee of Medical Journal Editors (ICMJE). The objective of this study was to assess association between authors' perceived importance of contributions for authorship qualification and their participation in manuscripts submitted to a journal. METHODS: Authors (n = 1181) of 265 manuscripts submitted to the Croatian Medical Journal were asked to identify and rate their contribution in the preparation of the submitted manuscript (0-none to 4-full for 11 listed contributions) and the importance of these contributions as authorship qualifications (0-none to 4-full). They were randomly allocated into 3 groups: the first (n = 90 manuscripts, n = 404 authors) first received the contribution disclosure form and then contribution importance-rating questionnaire; the second (n = 88 manuscripts, n = 382 authors) first received the rating questionnaire and then the contribution disclosure form, and the third group (n = 87 manuscripts, n = 395 authors) received both questionnaires at the same time. We compared authors' perception of importance of contribution categories. RESULTS: 1014 (85.9%) authors of 235 manuscripts responded. Authors who declared contribution to a specific category rated it as more important for authorship than those authors who did not contribute to the same category (P>0.005 for all contribution categories, Mann-Withney test). Authors qualifying for ICMJE authorship rated all contribution categories higher than non-qualifying authors. For all contributions, associations between perceived importance of contribution and actual author's contribution were statistically significant. CONCLUSIONS: Authorship seems to be not a normative issue subjective to categorization into criteria, but also a very personal view of the importance and value of one's contributions

Performance Evaluation of HARQ Technique with UMTS Turbo Code

The hybrid automatic repeat request technique (HARQ) represents the error control principle which combines an error correcting code and automatic repeat request procedure (ARQ), within the same transmission system. In this paper, using Monte Carlo simulation process, the characteristics of HARQ technique are determined, for the case of the Universal Mobile Telecommunication System (UMTS) turbo code

Energy detector performance in Rician fading channel

In this paper we analyzed the problem of detection of unknown signals in the Rician fading channel. A closed-form expression for the probability of detection is derived, followed by the numerical results. The analysis was extended to the case of cooperative sensor network in which the environment can be modelled by independent Rician fading channels

Performance Analysis of Iterative Decoding Algorithms for PEG LDPC Codes in Nakagami Fading Channels

In this paper we give a comparative analysis of decoding algorithms of Low Density Parity Check (LDPC) codes in a channel with the Nakagami distribution of the fading envelope. We consider the Progressive Edge-Growth (PEG) method and Improved PEG method for the parity check matrix construction, which can be used to avoid short girths, small trapping sets and a high level of error floor. A comparative analysis of several classes of LDPC codes in various propagation conditions and decoded using different decoding algorithms is also presented