327 research outputs found
A review of the Collyriinae (Hymenoptera: Ichneumonidae)
The species of the subfamily Collyriinae are reviewed. A new species from Turkey is described. A key for identification of the species is proposed
Wireless model-based predictive networked control system over cooperative wireless network
Owing to their distributed architecture, networked control systems (NCSs) are proven to be feasible in scenarios where a spatially distributed feedback control system is required. Traditionally, such NCSs operate over real-time wired networks. Recently, in order to achieve the utmost flexibility, scalability, ease of deployment, and maintainability, wireless networks such as IEEE 802.11 wireless local area networks (LANs) are being preferred over dedicated wired networks. However, conventional NCSs with event-triggered controllers and actuators cannot operate over such general purpose wireless networks since the stability of the system is compromised due to unbounded delays and unpredictable packet losses that are typical in the wireless medium. Approaching the wireless networked control problem from two perspectives, this work introduces a practical wireless NCS and an implementation of a cooperative medium access control protocol that work jointly to achieve decent control under severe impairments, such as unbounded delay, bursts of packet loss and ambient wireless traffic. The proposed system is evaluated on a dedicated test platform under numerous scenarios and significant performance gains are observed, making cooperative communications a strong candidate for improving the reliability of industrial wireless networks
Realization of a single-chip, SiGe:C-based power amplifier for multi-band WiMAX applications
A fully-integrated Multi-Band PA using 0.25 μm SiGe:C process with an output power of above 25 dBm is presented. The behaviour of the amplifier has been optimized for multi-band operation covering, 2.4 GHz, 3.6 GHz and 5.4 GHz (UWB-WiMAX) frequency bands for higher 1-dB compression point and efficiency. Multi-band operation is achieved using multi-stage topology. Parasitic components of active devices are also used as matching components, in turn
decreasing the number of matching component. Measurement results of the PA provided the following performance parameters: 1-dB compression point of 20.5 dBm, gain value of 23 dB and efficiency value of %7 operation for the 2.4 GHz band; 1-dB compression point of 25.5 dBm, gain value of 31.5 dB and efficiency value of %17.5 for the 3.6 GHz band; 1-dB compression point of 22.4 dBm, gain value of 24.4 dB and efficiency value of %9.5 for the 5.4 GHz band. Measurement
results show that using multi-stage topologies and implementing each parasitic as part of the matching network component has provided a wider-band operation with higher output power levels, above 25 dBm, with SiGe:C process
Spontaneous Subdural Haematoma Developing Secondary to Arachnoid Cyst Rupture
Arachnoid cysts are congenital, benign, non-neoplastic, extra-axial intra-arachnoidal lesions. Arachnoid cysts rarely become symptomatic, with bleeding. Intracranial haemorrhage as a complication of arachnoid cyst is a very rare condition. It is well-known that mid-cranial fossa cysts might cause intracerebral haemorrhage or subdural haematoma secondary to traumas. However, the occurrence of spontaneous subdural haematoma secondary to arachnoid cysts, developing without any trauma, is even rarer. A 17-year-old boy presenting with diplopia and headache, with no history of trauma, was diagnosed with left temporal lobe arachnoid cyst and left fronto-parietal subdural haematoma. He was operated on, solely for his haematoma, with no intervention performed for the arachnoid cyst. Authors suggest that it is sufficient to perform an operation for the haematoma only - without arachnoid cyst resection-if there is no clinical presentation specific to the arachnoid cyst itself
Zafernâme of Abdî
Fetihnâme, gazanâme, gazavatnâme türlerindeki eserler, ilk elden tarihî bilgi içermeleri sebebiyle tarih bilimi için önemli kaynaklardandır. Bununla birlikte bu eserlerin çoğunlukla sanatçı kimliği olan şairler/yazarlar tarafından kaleme alınmış olması, onları edebiyat araştırmaları için de önemli kaynaklar hâline getirir. Bu durum, söz konusu metinlerin sadece bir edebî şahsiyet tarafından yazılmasıyla ilgili değildir. Bu tür eserlerde yazarlar/şairler, bir sanatçı duyarlılığıyla çıkılan seferin, yapılan savaşın, kazanılan zaferin, yapılan antlaşmanın toplumda nasıl bir etkiye yol açtığını da yansıtırlar. Böylelikle eser, resmî tarihten farklı olarak dönem toplumunun zihniyetiyle ilgili çıkarımlar yapılabilecek bir belge niteliği kazanır Bu makalede Sarhoş Abdî'nin, içerdiği tarihî bilgilerle ve edebî yönüyle dikkat çeken Zafernâme'si incelenecek ve eserin çevriyazılı metni verilecektir. Genel olarak eserin konusunu, Vezir-i Azam Sinan Paşa'nın 1593-1594 yıllarında Avusturyalılara karşı düzenlediği Nemçe (Avusturya) seferi oluşturmaktadır. Mesnevi nazım şekliyle kaleme alınmış olan Zafernâme'de, Nemçe seferi çerçevesinde Tata [Bespirem/Pespirim (: Weszprem)], Papa, Senmarten (Saint Martin) ve Yanık (Raab, Györ) kalelerinin fethi anlatılmıştır. Mesneviden önce bir dibace yer almaktadır. Maddi bir beklenti içerisinde olduğu anlaşılan Abdî, başka edebî anlatılara da konu olan bu zaferleri kısaca tasvir etmiştir. Şair, kronolojik ayrıntılara ve detaylı tarihî bilgilere girmeden seferin ve yapılan savaşların önemli gördüğü aşamalarına genel hatlarıyla değinmiş, padişahın, Vezir-i Azam Sinan Paşa'nın ve Osmanlı ordusunun savaş meydanındaki başarılarını övmüş, Nemçe (Avusturya) ordusunu yermiştir.The works of art in the type of fetihnâme, gazanâme, gazavatnâme are important resources for science of history as they include historical information from the first hand. However, these works have been written by poets/writers who have artist identity and it brings them as important resources as literature researches. This is not only related to its being a work of a literal person. In this kind of works, writers/poets reflect the effect of an agreement made, victory gained, war made, sail made on the society with an artist’s awareness. Thus, the work gains a sociological qualification to be able to make deductions regarding the mentality of the time society different from the official history. In this article, Zafernâme of Sarhoş (drunk) Abdî that attracts attention in terms of its historical information it includes will be examined and document of the work will be given. Generally, Nemçe (Austria), Grand Vizier Sinan Pasha organized against Austrians in 15931594 constitutes the subject of the work. In Zafernâme written as poetry (style of mathnawi), journey period of the army and conquest of Tata [Bespirem/Pespirim (: Weszprem)], Papa, Senmarten (Saint Martin) and Yanık (Raab, Györ) castles. There is a preamble before the mesnevi. Abdi who was understood that he was in a materialistic expectation, figured that battle subjected to other literal stories. The poet addressed the general lines of the important stages of the battles done without entering detailed historical information and chronological details praised the success of Ottoman Army, Sultan and Grand Vizier Sinan Pasha in the battlefield and reviled against Nemçe (Austria) army
İntrakranial kitlelerin bilgisayarlı tomografi rehberliğinde sterotaktik mikrocerrahi rezeksiyonu]
Stereotactic microsurgical techniques allow for the precise localization and resection of lesions in critical areas of cortex or deep within the brain and minimize operative exposure to the surrounding tissues. This study presents our experience with CT-guided stereotactic microsurgical resection of cerebral lesions using the Leksell frame. A total of 42 patients undergoing computerized tomography guided stereotactic microsurgical resection of cerebral lesions between June 2000 and September 2017 were included in the study. Clinical, radiological, histological and follow-up data were retrospectively evaluated. Pre-and post-operative general status of the patients was assessed by Karnofsky Performance Scale (KPS). Except for the subjects with high-grade gliomas, complete resection could be accomplished in all cases. Of the 24 cases with convulsions, a complete cessation of epileptic attacks was attained in 20 and a decrease in their number and frequency was noted in 4 cases. Overall, 20 patients had no change in the KPS score, while 28 patients had increased and two had decreased KPS scores. No postoperative mortality occurred. CT-guided stereotactic microsurgical craniotomy is a safe, reliable and effective technique, which is particularly useful for the surgical treatment of small, benign cranial lesions and cerebral metastases. © 2018, Logos Medical Publishing. All rights reserved
Numerical solutions of one-dimensional parabolic convection-diffusion problems arising in biology by the Laguerre collocation method
In this work, we present a numerical scheme for the approximate solutions of the one-dimensional parabolic convection-diffusion model problems. Diffusion models form a reasonable basis for studying insect and animal dispersal and invasion, which arise from the question of persistence of endangered species, biodiversity, disease dynamics, multi-species competition so on. Convection diffusion problem is also a form of heat and mass transfer in biological models. The presented method is based on the Laguerre collocation method used for these problems of differential equations.
In fact, the approximate solution of the problem in the truncated Laguerre series form is obtained by this method. By substituting truncated Laguerre series solution into the problem and by using the matrix operations and the collocation points, the suggested scheme reduces the problem to a linear algebraic equation system. By solving this equation system, the unknown Laguerre coecients can be computed. The accuracy and the efficiency of the method is showed by numerical examples and the comparisons by the other methods
Remote Cerebellar Haemorrhage Occurring after Transcranial Pituitary Surgery
Post supratentorial and spinal surgeries, in rare cases, Remote Cerebellar Haemorrhage (RCH) develops as a complication. Although the exact aetiology of RCH remains uncertain, excessive drainage of the Cerebrospinal Fluid (CSF) is accepted as the most possible cause. It has been suggested that overdrainage of CSF leads to stretching and resultantly tearing of the cerebellar veins. Early diagnosis and appropriate management decrease mortality and morbidity significantly. In this report, we present a case of RCH encountered on the third postoperative day of transcranial pituitary surgery and discuss the possible causative factors. Excessive loss of CSF is considered to be the major cause of RCH. To our knowledge this is the first case of RCH seen after transcranial macroadenoma surgery reported in the literature so far
Remote Cerebellar Haemorrhage after Burr Hole Drainage of Chronic Subdural Haematoma: A Case Report
Remote cerebellar haemorrhage (RCH) is an unusual complication of supratentorial neurosurgical procedures. Even the rarer is cerebellar haemorrhage occurring after supratentorial burr hole drainage of Chronic Subdural Haematoma (CSDH). The exact mechanism is still unclear despite some possible causative factors such as rapid evacuation of haematoma and overdrainage of CSF (Cerebrospinal Fluid). We report a 80-year-old male patient who developed cerebellar haemorrhage after burr hole drainage of left frontoparietal chronic subdural haematoma and discuss the possible aetiological mechanisms through the review of the current literature
A fully integrated low-power SiGe power amplifier for biomedical applications
In this work, a full-integrated very-low power SiGe Power Amplifier (PA) is realized using the IHP (Innovations for High Performance), 0.25μm-SiGe process. The behaviour of the amplifiers has been optimized for the 2.1-2.4 GHz frequency band for a higher 1-dB compression point and high efficiency at a lower supply voltage. The PA delivers an output power of 3.75 mW and 1.25 mW for 2V and 1V, respectively. The PA measurements yielded the following parameters; gain of 13 dB, 1-dB compression point of 5.7 dBm, and Power-Added-Efficiency of 30% for 2V supply voltage. The PA circuit can go down to 1V of supply voltage with a gain of 10 dB, 1-dB compression point of 1 dBm, and Power-Added-Efficiency of 20%. For both supply voltages, the input and the output of the circuit give good reflection performance. With this performance, the PA circuit may be used for low-power biomedical implanted transceiver systems
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