The minimum variance distortionless response beamformer for damage identification using modal curvatures

This study presents a damage identification procedure in beams based on the use of beamforming algorithms, which are mostly utilized in inverse problems of source identification and image reconstruction. We choose the modal curvatures as observed quantities and compare the performance of the Bartlett beamformer, minimum variance distortionless response (MVDR) processor, and of a conventional objective function based on the modal curvatures. By means of a set of experiments, we show that the MVDR processor can overcome some of the difficulties encountered with other estimators, especially in cases of slight damage, or damage located between two sensors. © 2023, Association of American Publishers. All rights reserved.2-s2.0-8515265642

On the arithmetic sums of Cantor sets

Let C_\la and C_\ga be two affine Cantor sets in $\mathbb{R}$ with similarity dimensions d_\la and d_\ga, respectively. We define an analog of the Bandt-Graf condition for self-similar systems and use it to give necessary and sufficient conditions for having \Ha^{d_\la+d_\ga}(C_\la + C_\ga)>0 where C_\la + C_\ga denotes the arithmetic sum of the sets. We use this result to analyze the orthogonal projection properties of sets of the form C_\la \times C_\ga. We prove that for Lebesgue almost all directions $\theta$ for which the projection is not one-to-one, the projection has zero (d_\la + d_\ga)-dimensional Hausdorff measure. We demonstrate the results on the case when C_\la and C_\ga are the middle-(1-2\la) and middle-(1-2\ga) sets

Sinop at the Travelogues

Seyahatname, Arapça gezmek, gezi anlamındaki seyâhat ile, Farsça risale, mektup anlamındaki nâme kelimelerinin birleşmesiyle oluşmuştur. En geniş anlamıyla seyahatname, herhangi bir gezgin veya gözlemcinin ziyaret ettiği belli bir coğrafi alana ve tarihsel döneme dair izlenimlerini ve topladığı bilgileri yazıya aktardığı metinlerdir. Seyyah tanımlaması, sadece yabancı topraklardan gelen gezginlerle sınırlı değildir, aynı zamanda ait olduğu topraklara dair izlenimlerini aktaran gözlemcileri de kapsar. Seyahatnameler, iletişim imkânlarının kısıtlı olduğu dönemlerde bilimsel ve kültürel gelişmelerin aktarıcısı konumunda olmuştur. 1453 öncesinde yazılan Anadoluya yönelik seyahatnameler, Haçlı seferlerine katılan görgü tanıklarının veya Anadoludan Asyaya uzanan ticaret yollarından geçen tacirlerin aktarımlarıdır. XV. yüzyılın son yarısında Suriye ve Mısırın Osmanlılar tarafından alınması, 1580li yıllarda Osmanlıdan Hindistana uzanan doğu ticaret yolunun önem kazanması, Osmanlının bir siyasi güç olarak yükselişi ve Avrupa devletleriyle yoğun ilişkilerin başlamasıyla, imparatorluk topraklarına yönelik seyahatnameler ivme kazanır. Öte yandan Doğu; hem ötekinin yaşadığı zengin ülke, hem de Hz. İsanın doğduğu, Hıristiyanlığı yaydığı ve çarmıha gerildiğine inanılan kutsal topraktır. Dolayısıyla Doğuya gitmek, Batılılar için kendi özüne dönüş anlamı taşımaktadır. Bu çalışmada Sinopun Türklere geçmesinden sonra, 13. yüzyıldan başlayarak bu şehre gelen Doğulu ve Batılı seyyahların yazdığı seyahatnameler, kronolojik olarak incelenmiştir.Seyahatname (Travelogue), consists of two words; seyahat in Arabic and nâme in Persian. Seyahatname in the broadest sense is the texts in which travelers and observers collect their impressions of a visited specific geographical area and/or information for a particular historical period. The definition of Seyyah (traveler) is not limited only to the foreign travelers but includes local observers who transfer their impressions for their own land also. Seyahatname s are the transmitters of scientific and cultural advancements where communication facilities are limited. The seyahatname s which has been written before 1453 and intended for Anatolia were the quotations of the eye witnesses of the crusaders or merchants who travelled from Anatolia to Asia. Seyahatname s on the territory of the empire gains momentum after invading of Syria and Egypt by the Ottomans, increasing importance of east trade lines from Ottomans to India by the years of 1580 s, the rise of Ottomans as a political power and beginning of intensive relations with European countries. On the other hand, East means both the rich land where the others are living and the holy land where it s believed that the Jesus was born and crucified. Traveling to east means returning to their self-essence. In this article, the seyahatnames, which has been written by eastern and western travelers coming to town beginning with 13th cent., after the Sinope captured by Turks are chronologically analyze

Calvarial bone defects in ovariectomised rats treated with mesenchymal stem cells and demineralised freeze-dried bone allografts

Background: The aim of the study was to investigate the ability of a combination of bone marrow mesenchymal stem cells (BM-MSCs) with and without demineralised freeze-dried bone allografts (DFDBAs) to induce bone regeneration incalvarial defects in ovariectomised rats.Materials and methods: Critical size defects were filled with a combination of DFDBAs and BM-MSCs or BM-MSCs alone. Eight weeks after calvarial surgery, the rats were sacrificed. The samples were analysed histologically and immunohistochemically.Results: No difference was observed in vascularisation between groups C1 (animals with cranial defect only, control group) and O1 (animals with cranial defect only, ovariectomy group). Intramembranous ossification was observed at a limited level in groups C2 (animals with cranial defect with MSCs, control group) and O2 (animals with cranial defect with MSCs, ovariectomy group) compared to C1 and O1. In group C3 (animals with DFDBAs with MSCs, control group), the fibrous structures of the matrix became compact as a result of a bone graft having been placed in the cavity, but in group O3 (animals with DFDBAs with MSCs, ovariectomy group), the fibrous tissue was poorly distributed between the bone grafts for the most parts.Conclusions: We conclude that the insertion of BM-MSCs enhances bone healing; however, the DFDBA/BM-MSC combination has little effect on overcoming impaired bone formation in ovariectomised rats

The efficacy of tissue factor −603A/G and +5466A>G polimorphisms at the development of venous thromboembolism in cancer patients

Background and Aim: Venous thromboembolism (VTE) is one of the most common complications in cancer patients. Although factor V Leiden (FVL) is the most common genetic defect causing thrombosis, the impact of gene abnormalities on thrombotic tendency in cancer patients remains poorly explored. Tissue factor (TF) is a major physiologic initiator of blood coagulation. This is the first study regarding the association of TF gene −603A/G and +5466A>G polymorphisms with VTE in malignancy. Materials and Me thods: The study consists of two groups: cancer patients with VTE were included as Group 1 (n = 46); Group 2 comprises 196 cancer patients without VTE. Restriction fragment length polymorphism method was used for the detection of polymorphisms of TF −603A/G in the 5՛upstream region and TF 5466A/G in intron 2. FVL, PT G20210A and MTHFR C677T polymorphisms were determined by using commercially available Light Cycler kits. The genotype and allele frequencies between the groups were compared using χ² or Fisher exact test, if appropriate. Results: No differences were observed in the distribution of TF gene −603A/G genotype frequencies between the groups. Although a slightly increased incidence of +5466GA genotype was in Group 1 (17.4% vs 11.2%), it did not achieve statistical significance. The prevalence of FVL was significantly greater in Group 1 compared with Group 2 (41.3% vs 4.1%, p 0.05). Conclusions: The present study did not show significant association of TF gene −603A/G and +5466A>G polymorphisms with VTE in malignancy, however, further larger studies including different ethnic population are needed to confirm our findings.Background and Aim: Venous thromboembolism (VTE) is one of the most common complications in cancer patients. Although factor V Leiden (FVL) is the most common genetic defect causing thrombosis, the impact of gene abnormalities on thrombotic tendency in cancer patients remains poorly explored. Tissue factor (TF) is a major physiologic initiator of blood coagulation. This is the first study regarding the association of TF gene −603A/G and +5466A>G polymorphisms with VTE in malignancy. Materials and Me thods: The study consists of two groups: cancer patients with VTE were included as Group 1 (n = 46); Group 2 comprises 196 cancer patients without VTE. Restriction fragment length polymorphism method was used for the detection of polymorphisms of TF −603A/G in the 5՛upstream region and TF 5466A/G in intron 2. FVL, PT G20210A and MTHFR C677T polymorphisms were determined by using commercially available Light Cycler kits. The genotype and allele frequencies between the groups were compared using χ² or Fisher exact test, if appropriate. Results: No differences were observed in the distribution of TF gene −603A/G genotype frequencies between the groups. Although a slightly increased incidence of +5466GA genotype was in Group 1 (17.4% vs 11.2%), it did not achieve statistical significance. The prevalence of FVL was significantly greater in Group 1 compared with Group 2 (41.3% vs 4.1%, p 0.05). Conclusions: The present study did not show significant association of TF gene −603A/G and +5466A>G polymorphisms with VTE in malignancy, however, further larger studies including different ethnic population are needed to confirm our findings

Pre-operative Arterial Embolization of Symptomatic Giant Hemangioma of the Liver

Abstract: The cavernous hemangiomas of the liver are usually small sized and asymptomatic. Most of them are incidentally diagnosed and a very small portion requires therapy. Giant hemangioma can be symptomatic, and this condition is the indication for treatment. The striking complication of surgical treatment of cavernous hemangiomas is intra-operative bleeding. In this case, we aimed to demonstrate that the risk of intraoperative bleeding can be eliminated with the preoperative percutaneous trans-catheter arterial embolization technique

Sixty Years of Fractal Projections

Sixty years ago, John Marstrand published a paper which, among other things, relates the Hausdorff dimension of a plane set to the dimensions of its orthogonal projections onto lines. For many years, the paper attracted very little attention. However, over the past 30 years, Marstrand's projection theorems have become the prototype for many results in fractal geometry with numerous variants and applications and they continue to motivate leading research.Comment: Submitted to proceedings of Fractals and Stochastics