Sensing coverage and connectivity in cognitive radio sensor networks

Sensing coverage of a field of interest and connectivity are two very important performance measures in Wireless Sensor Networks (WSNs). Existing design methodologies and protocols for enhanced field sensing coverage and connectivity in WSNs are not directly applicable to Cognitive Radio Sensor Networks (CRSNs) due to their cognitive nature. In this chapter, the authors first review sensing coverage and connectivity models for traditional WSNs. Then, they propose novel approaches for sensing coverage and connectivity establishment in CRSN, benefiting from useful existing models from WSN and Cognitive Radio Ad Hoc Networks (CRAHNs). Proposed approaches span a wide variety of CRSN requirements and also point out open research problems in the field to guarantee sufficient sensing coverage quality and connectivity in CRSN

Construction of Stancu-Type Bernstein Operators Based on Bézier Bases with Shape Parameter λ

We construct Stancu-type Bernstein operators based on Bézier bases with shape parameter λ ∈ [ - 1 , 1 ] and calculate their moments. The uniform convergence of the operator and global approximation result by means of Ditzian-Totik modulus of smoothness are established. Also, we establish the direct approximation theorem with the help of second order modulus of smoothness, calculate the rate of convergence via Lipschitz-type function, and discuss the Voronovskaja-type approximation theorems. Finally, in the last section, we construct the bivariate case of Stancu-type λ -Bernstein operators and study their approximation behaviors

Mid-term implant survival, functional and radiological results and mechanical complications of mega-prosthetic reconstruction around the knee with the PENTA® system

© 2021, The Author(s).Aim: Mega-prosthetic reconstruction is the most common treatment method for massive osteoarticular defects caused by tumor resection around the knee. The new implant is a highly modular rotational-hinged megaprosthesis system with a distinct pentagonal stem geometry and variable implantation options. The aim of this study is to present the mid-term implant survival characteristics, functional and radiological results and mechanical complication profile of the new megaprosthesis. Methods: One hundred and one mega-prosthetic knee reconstruction procedures in 90 patients (M/F: 51/39) utilizing the new implant system were retrospectively analyzed. In 68 patients, the megaprosthesis was used for primary reconstruction following tumor resection while it was used for revision of other implants in 22. The mean age was 28.5 (7–66) years and the mean follow-up was 59.2 (24–124) months. The most common primary pathology was osteosarcoma with 63–70% patients, the most common anatomical site of involvement was the distal femur with 56–62% patients. Results: Henderson Type 2 failure (aseptic loosening) was seen in only 2–2.2% patients while Type 3 (structural failure) was seen in 29–32.2% Although the 5-year anchorage survival rate was 94.3%, overall mechanical implant survival was 76.1% at 5 years due to a relatively high failure rate in the first-generation hinge mechanism of the implant. The 5-year hinge survival rate demonstrated a significant improvement rate from 61.7% to 87.2% between the first and second generations of the implant (p = 0.027). The mean MSTS score was 24 out of 30 (14–29). The mean cumulative ISOLS radiographic score for index megaprosthesis operations was 19.7 (12–24), which corresponded to excellent outcome. Conclusion: The new megaprosthesis system is a reliable choice for the reconstruction of tumor-related massive osteoarticular defects around the knee. Although long-term follow-up is necessary for a definitive evaluation of the implant\"s survival characteristics, midterm follow-up yields exceptional anchorage properties related to pentagonal stem geometry with very good functional outcomes

The 2017-2018 Seasons at Çadir Höyük on the North Central Plateau

The Çadır Höyük mound is located in Yozgat Province, approximately 16 km from the city of Sorgun. Work commenced at the site in 1993 with an intensive surface survey, followed by excavation beginning in 1994. The deep sounding (excavated from 1994-2001) demonstrated that occupation stretches back to at least 5200 cal. BC; excavations on the mound summit indicate that occupation continued until a final abandonment perhaps in the 13th century CE. No gap in occupation of the mound over some six thousand years has been detected. The findings presented here derived from our work in three main periods represented at the site: the Late Chalcolithic exposure (ca. 3800-3500 BCE) located on the lower southern slope, the second and first millennium BCE, excavated in several areas of the site (the western slope work is presented here), and the Byzantine occupation, ca. 6th-13th centuries BCE on the mound summit, including mention of possible Roman architecture discovered in the 2018 season. The 2017 season provided some major discoveries, including three important child burials in the Late Chalcolithic area, a new gate and entryway into the Byzantine summit area, and a possible chapel. The 2018 season was devoted to further exploring these and other discoveries made in previous seasons in an attempt to solve major questions in preparation for a planned study season in 2019. By the close of the 2018 season we had achieved many of our goals; our work and interpretations are presented herein