23 research outputs found

    Computationally efficient solution for multilayer microwave circuits

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    The Spectral Domain Method (SDM) is widely applied to analyse two layer planar microwave circuits. Adaptation of this technique to multilayer structures requires an efficient derivation of the Green’s function. This paper provides an iterative derivation for computer design tool programmers

    A new approach to spectral domain method: Functional programming

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    The Spectral Domain Method (SDM) is a powerful technique to analyze planar microwave circuits. But available conventional programming languages used in the literature do not give enough speed to use the Spectral Domain Method to develop package analysis program. The functional approach to Spectral Domain Method gives a high level of programming and a variety of features which help to build elegant, powerful and general libraries of functions

    Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

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    PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

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    PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    DAİRESEL DALGA KILAVUZLARININ OPTİMİZE EDİLMİŞ İLETİM HATTI MATRİS MODELİ İLE TAM DALGA ANALİZİ

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    Düşük firekaslarda kullanılan yaklaşımlar yüksek frekanslarda geçerli olmadığında analizde tam-dalga yöntemlerinin kullanılması bir zorunluluktur. İletim Hattı Matrisi Modeli (TLM) bir tam-dalga analiz yöntemi olup literatürde elektromanyetik olayların analizinde sıklıkla kullanılmaktadır. Ancak bu modelde sınır şartlarından kaynaklanan yansıma, aşma, üst üste binme, bozulma, sinyal bütünlüğünün bozulması gibi çeşitli problemler ile karşılaşılmaktadır. Bu çalışmada TLM yönteminde sınır şartlarının kolay uygulanabilmesi için optimizasyon yapılmıştır. Optimizasyonun başarısını göstermek içinde örnek olarak analizi daha komplex olan dairesel dalga klavusu kullanılmıştır. Bu yayında X bandında (8-12 GHz) kullanılan WC-94 adlı dairesel dalga kılavuzu TE ve TM modu için ayrı ayrı, optimize edilmiş TLM yöntemi ile analiz edilmiştir. Sonuçların doğrulugu ve sunulan optimizasyon yönteminin başarısı ayrıntıları ile sunulmuştur

    KABLOSUZ ALGILARICILARIN GÜNCEL KULLANIM ALANLARI

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    Teknolojinin gelişmesi ile algılayıcıların hem boyutları küçülmüş, hem de kapasiteleri ve işlevselliği artmıştır. Algılayıcılar günümüzde sıcaklıkta basınç olçmeye, hız haraket ve yön takibine kadar birçok notkada yaygın olarak kullanılmaktadır. Bu yaygın kullanımına paralel olarak kablosuz algılayıcılar üzerine yüzlerce akademik çalışma yapılmaktadır. Bu yayında kablosuz algılayıcılara ilgi duyan yeni araştırmacılara ışık tutabilmek için kablosuz algılayıcıların kullanım alanları kaynaklar ışığında açıklanmıştır
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