Factor Graph Based LMMSE Filtering for Colored Gaussian Processes

We propose a low complexity, graph based linear minimum mean square error (LMMSE) filter in which the non-white characteristics of a random process are taken into account. Our method corresponds to block LMMSE filtering, and has the advantage of complexity linearly increasing with the block length and the ease of incorporating the a priori information of the input signals whenever possible. The proposed method can be used with any random process with a known autocorrelation function with the help of an approximation to an autoregressive (AR) process. We show through extensive simulations that our method performs very close to the optimal block LMMSE filtering for Gaussian input signals.Comment: 5 pages, 4 figure

A Low-Complexity Graph-Based LMMSE Receiver Designed for Colored Noise Induced by FTN-Signaling

We propose a low complexity graph-based linear minimum mean square error (LMMSE) equalizer which considers both the intersymbol interference (ISI) and the effect of non-white noise inherent in Faster-than-Nyquist (FTN) signaling. In order to incorporate the statistics of noise signal into the factor graph over which the LMMSE algorithm is implemented, we suggest a method that models it as an autoregressive (AR) process. Furthermore, we develop a new mechanism for exchange of information between the proposed equalizer and the channel decoder through turbo iterations. Based on these improvements, we show that the proposed low complexity receiver structure performs close to the optimal decoder operating in ISI-free ideal scenario without FTN signaling through simulations.Comment: 6 pages, 6 figures, IEEE Wireless Communications and Networking Conference 2014, Istanbul, Turke

Homologous Codes for Multiple Access Channels

Building on recent development by Padakandla and Pradhan, and by Lim, Feng, Pastore, Nazer, and Gastpar, this paper studies the potential of structured nested coset coding as a complete replacement for random coding in network information theory. The roles of two techniques used in nested coset coding to generate nonuniform codewords, namely, shaping and channel transformation, are clarified and illustrated via the simple example of the two-sender multiple access channel. While individually deficient, the optimal combination of shaping and channel transformation is shown to achieve the same performance as traditional random codes for the general two-sender multiple access channel. The achievability proof of the capacity region is extended to the multiple access channels with more than two senders, and with one or more receivers. A quantization argument consistent with the construction of nested coset codes is presented to prove achievability for their Gaussian counterparts. These results open up new possibilities of utilizing nested coset codes with the same generator matrix for a broader class of applications

A Survey of Security in UAVs and FANETs: Issues, Threats, Analysis of Attacks, and Solutions

Thanks to the rapidly developing technology, unmanned aerial vehicles (UAVs) are able to complete a number of tasks in cooperation with each other without need for human intervention. In recent years, UAVs, which are widely utilized in military missions, have begun to be deployed in civilian applications and mostly for commercial purposes. With their growing numbers and range of applications, UAVs are becoming more and more popular; on the other hand, they are also the target of various threats which can exploit various vulnerabilities of UAV systems in order to cause destructive effects. It is therefore critical that security is ensured for UAVs and the networks that provide communication between UAVs. In this survey, we aimed to present a comprehensive detailed approach to security by classifying possible attacks against UAVs and flying ad hoc networks (FANETs). We classified the security threats into four major categories that make up the basic structure of UAVs; hardware attacks, software attacks, sensor attacks, and communication attacks. In addition, countermeasures against these attacks are presented in separate groups as prevention and detection. In particular, we focus on the security of FANETs, which face significant security challenges due to their characteristics and are also vulnerable to insider attacks. Therefore, this survey presents a review of the security fundamentals for FANETs, and also four different routing attacks against FANETs are simulated with realistic parameters and then analyzed. Finally, limitations and open issues are also discussed to direct future wor

Abutment Selection for Anterior Implant-Supported Restorations

With the introduction of dental implants to the market, varying restorative options have been successfully added for restoring the function and esthetics of both completely and partially edentulous patients. Accurate prosthodontic rehabilitation is the key factor for providing the long-term success and the survival of osseointegrated implants. Implant-supported restorations can be fabricated with different techniques. The prefabricated abutments provided by the implant companies are accepted as the gold standard because of their biocompatibility and advanced mechanical properties. However, especially for the anterior restorations, they are increasingly being replaced by custom abutments ideally prepared with CAD/CAM techniques; due to disadvantages of prefabricated abutments such as esthetic flaws, mechanical insufficiency resulting from implant placement, unacceptable emergence profile, and unhygienic regions formed under angled abutments. Currently, custom abutments are reported to have functional and esthetic advantages over prefabricated abutments. In this chapter, indications for proper abutment selection, contemporary production techniques, and different abutment materials will be stated, and the current research on the subject will be discussed

Evaluation of clinical, diagnostic and treatment aspects in hydatid disease: analysis of an 8-year experience

Background & Objective: Echinococcosis is still a common health problem. The aim of this study was to discuss our 8-year data in terms of diagnosis, treatment and follow-up of cystic Echinococcosis.Methods: A total of 178 patients who had hydatid cyst were analyzed retrospectively from the hospital records. The diagnosis of hydatid cyst was based on clinical-serological and radiological findings. Treatment response was evaluated with clinical, radiological and serological findings.Results: A total of 178 medical records were evaluated; the male:female ratio was 0.73 and mean age 44.6±16.9 years. The most common symptom was abdominal pain (94, 52.8%). The mean cyst size was 9.5±3.9 cm. Eosinophilia was significantly higher in patients with complicated cyst (35.3%) (p=0.002). The average duration of hospitalization in surgical patients was shorter than non-surgical patients (p=0.026). There was no significant correlation between the preference of scolicidal agent (hypertonic saline, H2O2, povidone iodine) and recurrence in patients who underwent surgery (p>0.05). There was no significant difference between the patients who underwent radical and conservative surgery in terms of complication and recurrence (p=0.077, p=0.557). No significant difference was found between percutaneous and surgical treatment in terms of complication and recurrence (p=0.264, p=0.276).Conclusion: Even though considerable progress has been made, uncertainties remain in the diagnosis and treatment of Echinococcosis. Hence, standardized diagnostic and treatment procedures should be established with well-designed studies.Keywords: Echinococcosis, hydatid cyst, diagnosis, treatment

Promising photodynamic antimicrobial activity of polyimine substituted zinc phthalocyanine and its polycationic derivative when conjugated to nitrogen, sulfur, co-doped graphene quantum dots against Staphylococcus aureus

Antimicrobial resistance is a most important problem facing the treatment of infectious diseases. Antimicrobial photodynamic therapy is an alternative treatment strategy, considered to be cost-effective and feasible. For this purpose, octa-imine substituted ZnPc (3) have been prepared and conjugated to nitrogen, sulfur co-doped graphene quantum dots (N,S-GQDs) through π-π stacking. The photophysical and photochemical properties of Pc alone and and Pc-conjugated to the GQD nanomaterial such as absorption, fluorescence, fluorescence life time, singlet oxygen quantum yields, triplet state quantum yields and exited state lifetimes were investigated in solutions before in vitro cell studies. The PACT activity of prepared structures was investigated against Gram-positive (Staphylococcus aureus). Our results suggest that the in the case of conjugation of zinc Pc to N,S-GQDs, photodynamic inactivation increased with the 100 % reduction percentage

Photodynamic inactivation of Staphylococcus Aureus with Schiff base substituted Zinc phthalocyanines through conjugation to silver nanoparticles

We present the preparation of Schiff base substituted neutral phthalocyanines derived from aldehyde-substituted phthalocyanine which are conjugated to silver nanoparticles through covalent-like strong interactions. The photophysicochemical properties of the nanoconjugates and the Pcs alone were studied comparatively. The photodynamic antimicrobial chemotherapy (PACT) activities. of prepared photosensitizers was investigated against Gram-positive bacterium (Staphylococcus aureus). Unlike Pcs alone, conjugated phthalocyanines to silver nanoparticles showed excellent photodynamic antimicrobial activity with the 100% reduction percentage upon illumination