A wideband trapezoidal dielectric resonator antenna with circular polarization

A new design of a circularly-polarized (CP) trapezoidal dielectric resonator antenna (DRA) for wideband wireless application is presented. A single-layered feed is used to excite the trapezoidal shaped dielectric resonator to increase resonant frequency and axial ratio. Besides its structure simplicity, ease of fabrication and low-cost, the proposed antenna features good measured impedance bandwidth, 87.3% at 4.21 GHz to 10.72 GHz frequency bands. Moreover, the antenna also produces 3-dB axial ratio bandwidth of about 710 MHz from 5.17 GHz to 5.88 GHz. The overall size of DRA is 21 mm × 35 mm, which is suitable for mobile devices. Parametric study and measurement results are presented and discussed. Very good agreement is demonstrated between simulated and measured results

Wideband P-Shaped Dielectric Resonator Antenna

A novel P-shaped dielectric resonator antenna (DRA) is presented and investigated for wideband wireless application. By using P-shaped resonator, a wideband impedance bandwidth of 80% from 3.5 to 8.2 GHz is achieved. The antenna covers all of wireless systems like C-band, 5.2, 5.5 & 5.8 GHz-WLAN & WiMax. The proposed antenna has a low profile and the thickness of the resonator is only 5.12 mm, which is 0.06-0.14 free space wavelength. A parametric study is presented. The proposed DRA is built and the characteristics of the antenna are measured. Very good agreement between numerical and measured results is obtained

A New Wideband Circularly Polarized Dielectric Resonator Antenna

A wideband and compact circularly polarized (CP) C-shaped dielectric resonator antenna (DRA) is presented. The proposed C-shaped DR is excited by a simple stripe line connected to a coplanar waveguide (CPW) feeding line. The C-shaped DRA is circularly polarized with 19% axial ratio (AR) bandwidth. It is found that the CP bandwidth can be expanded by using a narrow short circuit strip. The final design achieves CP with 50% AR bandwidth. The proposed circularly polarized DRA (CPDRA) with good radiation characteristics offers an impedance bandwidth of 58% between 3.45 and 6.26 GHz for VSWR ≤ 2. The proposed DRA is fabricated and tested. Very good agreement between simulated and measured results is obtained

Investigation of overhang effect on cutting tool vibration for tool condition monitoring

Vibration measurement is one of the most widely used indirect methods of tool condition monitring, but vibration signal features may be affected by overhang lenght. In turning process, it is known that for the best overall machining results, tool overhang should be kept to a minimum. However, a longer tool overhang may be required depending on the geometry of the workpiece and in situations such as internal turning process. The long overhang increases vibration. In this paper the relations between tool overhang and the most commonly used signal features is investigated

A report about a case of Gestational trophoblastic tumor associated with ectopic pregnancy

مقدمه: تومور تروفوبلاستیک حاملگیGTT)) متعاقب حاملگی خارج رحمی یک رویداد بسیار نادر است. در این مقاله یک مورد مول مهاجم که از یک حاملگی خارج رحمی لوله‌ای نشأت گرفته بود معرفی می‌شود. گزارش مورد: بیمار خانم 26 ساله با حاملگی دوم و اولین حاملگی خارج رحمی (G2L1EP1) بود که به خاطر افزایش میزان هورمون گنادوتروپین جفتی((BHCG بعد از عمل حاملگی خارج رحمی (EP) به بیمارستان شهید بهشتی اصفهان ارجاع شد. درمان اولیه EP بیمار با عمل سالپنژکتومی بوده است. پیگیری پاتولوژی سالپنژکتومی مول مهاجم تشخیص داده شد که بیمار تحت دو دوره درمان با متوترکسات قرار گرفت و با توجه به گزارش توده در آدنکس راست در سونوگرافی یک نوبت لاپاراتومی ‌شد که باز هم تشخیص مول مهاجم بود. بنابراین بیمار تحت رژیم درمانی (etoposide methotrexate actinomycin D cyclophosphamide vincristine) EMA/CO قرار گرفت و نهایتاً با BHCG معادل 1 مرخص شد. نتیجه گیری: پیگیری عدد BHCG بعد از عمل جراحی EP هم برای تشخیص EP پا برجا و هم برای رد GTT بسیار مهم است هم چنین پیگیری جواب پاتولوژی اعمال جراحی در صورتی که از تشخیص نیز مطمئن هستیم ضرورت دارد

QED: using Quality-Environment-Diversity to evolve resilient robot swarms

In swarm robotics, any of the robots in a swarm may be affected by different faults, resulting in significant performance declines. To allow fault recovery from randomly injected faults to different robots in a swarm, a model-free approach may be preferable due to the accumulation of faults in models and the difficulty to predict the behaviour of neighbouring robots. One model-free approach to fault recovery involves two phases: during simulation, a quality-diversity algorithm evolves a behaviourally diverse archive of controllers; during the target application, a search for the best controller is initiated after fault injection. In quality-diversity algorithms, the choice of the behavioural descriptor is a key design choice that determines the quality of the evolved archives, and therefore the fault recovery performance. Although the environment is an important determinant of behaviour, the impact of environmental diversity is often ignored in the choice of a suitable behavioural descriptor. This study compares different behavioural descriptors, including two generic descriptors that work on a wide range of tasks, one hand-coded descriptor which fits the domain of interest, and one novel type of descriptor based on environmental diversity, which we call Quality-Environment-Diversity (QED). Results demonstrate that the above-mentioned model-free approach to fault recovery is feasible in the context of swarm robotics, reducing the fault impact by a factor 2-3. Further, the environmental diversity obtained with QED yields a unique behavioural diversity profile that allows it to recover from high-impact faults