Space scanning FMCW-based two-dimensional frequency diverse array radar

The frequency-modulated continuous wave (FMCW)-based frequency diverse array (FDA) radar concept is extended to two dimensions (2D). The radar operates as a linear pulsed FMCW/FDA in the transmission (TX) mode while it operates as a pulsed FMCW/phased array (PA) in the receiving mode. It is shown that the FDA has the capability of scanning a 2D angular sector in a single pulse TX. It is shown that local instantaneous frequency bandwidth is much smaller than the radiofrequency (RF) frequency deviation of linear frequency modulation. Positive and negative slope TX/RF locations offer frequency diversity. The low signal-to-noise ratio of FDA is well compensated due to target temporal decorrelation diversity in the observation time and by the cumulative detection scheme used. Time domain and frequency domain signal processings are described. A Kuband direct digital synthesis-based FDA radar design is compared by a corresponding equivalent PA radar

A case of primary hypoparathyroidism presenting with acute kidney injury secondary to rhabdomyolysis

Hypoparathyroidism is the most common cause of symmetric calcification of the basal ganglia. Herein, a case of primary hypoparathyroidism with severe tetany, rhabdomyolysis, and acute kidney injury is presented. A 26-year-old male was admitted to the emergency clinic with leg pain and cramps, nausea, vomiting, and decreased amount of urine. He had been treated for epilepsy for the last 10 years. He was admitted to the emergency department for leg pain, cramping in the hands and legs, and agitation multiple times within the last six months. He was prescribed antidepressant and antipsychotic medications. He had a blood pressure of 150/90 mmHg, diffuse abdominal tenderness, and abdominal muscle rigidity on physical examination. Pathological laboratory findings were as follows: creatinine, 7.5 mg/dL, calcium, 3.7 mg/dL, alanine transaminase, 4349 U/L, aspartate transaminase, 5237 U/L, creatine phosphokinase, 262.000 U/L, and parathyroid hormone, 0 pg/mL.There were bilateral symmetrical calcifications in basal ganglia and the cerebellum on computerized tomography. He was diagnosed as primary hypoparathyroidism and acute kidney injury secondary to severe rhabdomyolysis. Brain calcifications, although rare, should be considered in dealing with patients with neurological symptoms, symmetrical cranial calcifications, and calcium metabolism abnormalities

Calprotectin levels in patients with rheumatoid arthritis to assess and association with exercise treatment

Rheumatoid arthritis (RA) is a chronic, inflammatory, and autoimmune disease that can cause permanent joint damage. In our study, we aim to analyze the change in calprotectin levels following the low-density exercise levels applied to the patients with RA. Twenty-eight patients with RA and 30 healthy controls were included in this study. To evaluate the activity of disease in RA, scores of disease activity that has increased (DAS-28) are figured. Calprotectin, nitric oxide (NO), white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and rheumatoid factor (RF) levels are tested as the laboratory evaluation. Calprotectin, NO, CRP, ESR, WBC, and RF levels were significantly higher in the patient group compared to the control group (p < 0.01, p < 0.001, p < 0.01, p < 0.01, p < 0.01, and p < 0.05, respectively). In correlation analysis applied to the patient group with RA, there has been determined a positive relation with calprotectin, and DAS-28, CRP, NO, RF, and WBC (p < 0.001, p < 0.05, p < 0.001, p < 0.05, and p < 0.05, respectively). In result of the low-density exercise treatment applied to patients with RA for 8 weeks, there has been determined a significant decrease in calprotectin, DAS-28, NO, CRP, ESR, and RF levels (p < 0.05, p < 0.001, p < 0.01, p < 0.05, p < 0.05, and p < 0.05, respectively). As a result, a significant relation is found between RA disease activity and calprotectin levels and other inflammatory parameters. At the same time, it shows that calprotectin which is a significant indicator of local inflammation can be used as a good identifier in following up exercise treatment

GSM uygulamaları için genlik karşılaştırma ile yön bulmanın deneysel performans değerlendirilmesi.

In this thesis, radio direction finding (DF) systems are examined, implementation and measurements for GSM mobile phones are done by using 6-element uniform circular Vivaldi antenna array and uniform circular monopole antenna array which is used asWatsonWatt antenna. Although degrading in performance of DF is expected, only one receiver unit is used in angle-of-arrival (AOA) to measure received signal strength (RSS) from each antenna elements to obtain low cost and small sized set-up. Moreover three di erent algorithms are implemented with the DF arrays Least Square (MLS), Maximum Likelihood (ML) and Multiple Signal Characterization(MUSIC). Finally experimental performance evaluation of amplitude comparison DF set-ups with single receiver will be given in this study.M.S. - Master of Scienc

İKİ BOYUTLU DOĞRUSAL KİPLEMELİ AYRIK FREKANS ANTEN DİZİSİ TASARIMI VE PERFORMANS DEĞERLENDİRİLMESİ

Waveform diversity is a highly desired property for radars because of its numerous benefits. Frequency diversity is one type of the waveform diversity. Total radiation pattern of transmitting antenna elements that are operating at slightly different center frequencies has peaks and nulls depending on the summation of the radiated fields, which can be constructive or destructive with respect to location and time. LFM chirp fed antenna elements with increasing true time delays will give rise to frequency diversity, thus, self-scanning beam patterns. This is named as LFMCW based FDA in the literature. In this thesis, a direction finding method with LFMCW based linear FDA is presented and evaluated. Furthermore, comparison with a proven MIMO example that focuses on advantages of spatially modulated array takes place. It is shown in this study that one can obtain comparable performance by using much simpler LFMCW–FDA implementation than state of the art MIMO implementations which are relatively more complex in structure. Waveform diversity properties and application methods of LFMCW-FDA are both analytically and experimentally proven for radar implementation by [1]–[5]. All of them utilized the linear array until now. In this study, a novel implementation with a planar antenna array is introduced. Migration to planar array makes 3D scanning possible with this technic. The proposed structure is evaluated by simulations of a realistic radar example. Finally, the target RCS characteristic of the planar array is investigated and compared with the equivalent PA radar.Dalga şekli çeşitlendirilmesi birçok faydası sebebiyle radar uygulamalarında sık sık istenen bir tekniktir. Dalga çeşitlendirme tekniklerinden biri de frekans çeşitlendirme yöntemidir. Merkez frekansları çok hafif farklı olan sinyallerin kullanıldığı antenlerin oluşturduğu dizilerinin toplam ışıma örüntüsünde gönderilen sinyallerin toplam girişim fazlarına bağlı olarak tepeler ve vadiler oluşur. Dizi antenlerinin arasında frekans çeşitliliği yaratabilmek için farklı teknikler kullanılabilir. Doğrusal frekans modülasyonuna sahip işaret, gerçek zamanlı gecikme yolları vasıtasıyla bir anten dizisi beslendiğinde elemanlar arası frekans farkı, dolayısıyla kendiliğinden uzayı tarayan hüzmeler, elde edilebilir. Bu yöntem literatürde doğrusal frekans modülasyonlu devamlı dalgaya dayalı ayrık frekans dizisi (LFMCW-FDA) olarak adlandırılır. Bu çalışma kapsamında LFMCW-FDA mantığıyla kurulmuş doğrusal anten dizisi kullanılarak yeni bir yön bulma (DF) metodu sunulmakta ve değerlendirilmektedir. Bunun da ötesinde, literatürdeki uzaysal modülasyonun avantajlarına odaklanılmaktatır; işlevselliği kanıtlanmış olan çoklu giriş-çoklu çıkış anten dizisi (MIMO) örneği ile karşılaştırmalar yer almaktadır. Bu çalışmada uygulaması çok daha kolay olan LFMCW-FDA tekniğinden, en gelişmiş yöntemlerden olan MIMO uygulamasıyla denk performansa erişilebileceği gösterilmiştir. LFMCW-FDA yöntemi hem analitik olarak hem deneysel olarak radar uygulamaları için kanıtlanmış bir tekniktir [1]–[5]. Şimdiye kadar bu örneklerin her biri doğrusal anten dizilerinden faydalanmaktadır. Bu çalışmalarda gösterilen avantajlar uygulama kolaylığı, çoklu yansıma koşulları altında etkinliği ve hedef kesit alanın daha az dalgalanmasıdır. Literatüre başka bir katkı olarak, yeni bir LFMCW-FDA yönteminden faydalanan düzlemsel anten dizisi sunulmaktadır. Bu gelişme ile üç boyutlu tarama mümkün kılınmaktadır. Bu yeni yöntem gerçekçi radar senaryoları ile değerlendirilmektedir. Son olarak bu radar kullanılarak hedef radar kesit alanının karakteristik özellikleri araştırılmış ve eş değer nitelikteki faz dizili radarla elde edilmiş değerler ile karşılaştırılmıştır.Ph.D. - Doctoral Progra

Design and Implementation of Transmitting and Receiving Antenna Pair on Flat Ring Surface

In this work, design and implementation of broadside altimeter antenna on circular ring surface are performed. Utilizing array factor formulation, possible locations for circular array elements are chosen. Slitted microstrip patch antennas are used for an efficient design. Satisfactory results are obtained for an altimeter antenna that can be utilized in missile, aircraft or spacecraft applications

Effects of fluoroscopy-guded intraartcular injecton, suprascapular nerve block, and combnaton therapy n hemplegc shoulder pan: a prospective double-blnd, randomzed clncal study

ObjectiveTo investigate the effect and superiority of fluoroscopy-guided intraarticular shoulder injection (IAI), suprascapular nerve block (SSNB), and combination treatment in hemiplegic shoulder pain (HSP).DesignWe included 30 patients diagnosed with HSP. Patients were divided into three groups: IAI, SSNB, and combination treatment. Patients were assessed using a visual analogue scale (VAS) prior to the injection and at hour 1, week 2, and month 2 after the injection, with goniometry at two angles at the moment that pain started and maximum passive range of motion (ROM) of the shoulder and Modified Barthel Index prior to the injection, at week 2 and month 2 after the injection.ResultsSignificant decrease in the VAS and increase in shoulder passive ROMs were detected at all follow-ups in groups. In comparison, there was no significant difference in VAS scores. Change in the internal rotation at the moment that pain started was found to be higher in the patients treated with the combined method than the other methods. Change in maximum passive ROMs was similar between treatment groups.ConclusionIAI, SSNB, and the combination treatments are reliable and effective treatment modalities that provide pain relief and an increase in shoulder passive ROMs in HSP