A New Kind of Slant Helix in Lorentzian (n + 2)- Spaces

Ates, Fatma,Gok, Ismail,Ekmekci, Faik Nejat Department of Mathematics 2016 Kyungpook mathematical journal Vol.56 No.3

In this paper, we introduce a new kind of slant helix for null curves called null $W_n$-slant helix and we give a definition of new harmonic curvature functions of a null curve in terms of $W_n$ in (n + 2)-dimensional Lorentzian space $M^{n+2}_1$ (for n > 3). Also, we obtain a characterization such as: "The curve ${\alpha}$ s a null $W_n$-slant helix ${\Leftrightarrow}H^{\prime}_n-k_1H_{n-1}-k_2H_{n-3}=0$" where $H_n,H_{n-1}$ and $H_{n-3}$ are harmonic curvature functions and $k_1,k_2$ are the Cartan curvature functions of the null curve ${\alpha}$.

ON THE GEOMETRY OF THE CROSSED PRODUCT OF GROUPS

Ates, Firat,Cevik, Ahmet Sinan,Karpuz, Eylem Guzel Korean Mathematical Society 2021 대한수학회보 Vol.58 No.5

In this paper, firstly, we work on the presentation of the crossed product of groups of general types. After that we find the generating pictures (Second Homotopy Group) of this product by looking the relations from a geometric viewpoint. Finally, we give some applications.

Earthquake response of isolated cable-stayed bridges under spatially varying ground motions

Ates, Sevket,Soyluk, Kurtulus,Dumanoglu, A. Aydin,Bayraktar, Alemdar Techno-Press 2009 Structural Engineering and Mechanics, An Int'l Jou Vol.31 No.6

A comprehensive investigation of the stochastic response of an isolated cable-stayed bridge subjected to spatially varying earthquake ground motion is performed. In this study, the Jindo Bridge built in South Korea is chosen as a numerical example. The bridge deck is assumed to be continuous from one end to the other end. The vertical movement of the stiffening girder is restrained and freedom of rotational movement on the transverse axis is provided for all piers and abutments. The longitudinal restraint is provided at the mainland pier. The A-frame towers are fixed at the base. To implement the base isolation procedure, the double concave friction pendulum bearings are placed at each of the four support points of the deck. Thus, the deck of the cable-stayed bridge is isolated from the towers using the double concave friction pendulum bearings which are sliding devices that utilize two spherical concave surfaces. The spatially varying earthquake ground motion is characterized by the incoherence and wave-passage effects. Mean of maximum response values obtained from the spatially varying earthquake ground motion case are compared for the isolated and non-isolated bridge models. It is pointed out that the base isolation of the considered cable-stayed bridge model subjected to the spatially varying earthquake ground motion significantly underestimates the deck and the tower responses.

Feasibility Study of Sideway Block System Using Geopolymer Mortar Containing Cork Waste as Fine Aggregate

Ates, Fatmanur(아테스 파트마눌),Park, Kyu Tae(박규태),Woo, Byeong-Hun(우병훈),Kim, Kyeong Woo(김경우),Kim, Hong Gi(김홍기),Ryou, Jae-Suk(류재석) 한국콘크리트학회 2023 한국콘크리트학회 학술대회 논문집 Vol.35 No.1

Association Between High Platelet Indices and Proteinuria in Patients With Hypertension

Ihsan Ates,Mesudiye Bulut,Nihal Ozkayar,Fatih Dede 대한진단검사의학회 2015 Annals of Laboratory Medicine Vol.35 No.6

Background: We aimed to determine the association between platelet indices including plateletcrit (PCT), mean platelet volume (MPV), platelet distribution width (PDW), and proteinuria associated with hypertension (HT) as well as the relative power of each to predict proteinuria. Methods: The study included 223 patients (68 men and 155 women) with primary HT. PCT, MPV, PDW, and proteinuria levels were measured. The patients were divided into two groups according to proteinuria status based on 24-hr urinary protein excretion: proteinuria (+) group (15 men and 40 women) and proteinuria (-) group (53 men and 115 women). Results: The mean and SD of platelet count, PDW, PCT, and MPV were 278.8±49.6 ×109/L, 13.5±1.8%, 0.31±0.07%, and 11.3±2.6 fL, respectively. The mean platelet count, PCT, MPV, and PDW were significantly higher in the proteinuria (+) group than in the proteinuria (-) group (P<0.05); there were no significant differences in the other blood parameters between the two groups. The platelet count, PCT, MPV, and PDW were independent risk factors predictive of proteinuria according to a stepwise regression analysis of PDW, PCT, and MPV. PCT was the strongest independent predictor of proteinuria. Conclusions: The platelet indices PCT, PDW, and MPV were significantly higher in patients with proteinuria than in those without it. Among these three indices, PCT was the strongest predictor of proteinuria.

Review : The Pathogenesis and Management of Achalasia: Current Status and Future Directions

( Fehmi Ates ),( Michael F Vaezi ) 대한간학회 2015 Gut and Liver Vol.9 No.4

Achalasia is an esophageal motility disorder that is commonly misdiagnosed initially as gastroesophageal reflux disease. Patients with achalasia often complain of dysphagia with solids and liquids but may focus on regurgitation as the primary symptom, leading to initial misdiagnosis. Diagnostic tests for achalasia include esophageal motility testing, esophagogastroduodenoscopy and barium swallow. These tests play a complimentary role in establishing the diagnosis of suspected achalasia. High-resolution manometry has now identified three subtypes of achalasia, with therapeutic implications. Pneumatic dilation and surgical myotomy are the only definitive treatment options for patients with achalasia who can undergo surgery. Botulinum toxin injection into the lower esophageal sphincter should be reserved for those who cannot undergo definitive therapy. Close follow-up is paramount because many patients will have a recurrence of symptoms and require repeat treatment. (Gut Liver 2015;9:449-463)

Combined factor V and VIII deficiency in a young woman with abundant bleeding after tooth extraction

Ihsan Ates,Mustafa Kaplan,Gul Tokgoz,Funda Ceran,Simten Akalın,Gulsum Ozet 대한혈액학회 2016 Blood Research Vol.51 No.1

None

Investigation of effectiveness of double concave friction pendulum bearings

Sevket Ates 사단법인 한국계산역학회 2012 Computers and Concrete, An International Journal Vol.9 No.3

This paper presents the investigation of the stochastic responses of seismically isolated bridges subjected to spatially varying earthquake ground motions including incoherence, wave-passage and site-response effects. The incoherence effect is examined by considering Harichandran and Vanmarcke coherency model. The effect of the wave-passage is dealt with various wave velocities in the response analysis. Homogeneous firm, medium and soft soil conditions are selected for considering the siteresponse effect where the bridge supports are constructed. The ground motion is described by filtered white noise and applied to each support points. For seismic isolation of the bridge, single and double concave friction pendulum bearings are used. Due to presence of friction on the concave surfaces of the isolation systems, the equation of motion of is non-linear. The non-linear equation of motion is solved by using equivalent linearization technique of non-linear stochastic analyses. Solutions obtained from the stochastic analyses of non-isolated and isolated bridges to spatially varying earthquake ground motions compared with each other for the special cases of the ground motion model. It is concluded that friction pendulum systems having single and double concave surfaces have important effects on the stochastic responses of bridges to spatially varying earthquake ground motions.

Effects of soil-structure interaction on construction stage analysis of highway bridges

Sevket Ates,Barbaros Atmaca,Erdal Yildirim,Nurcan Asci Demiroz 사단법인 한국계산역학회 2013 Computers and Concrete, An International Journal Vol.12 No.2

The aim of this paper is to determine the effect of soil-structure interaction and time dependent material properties on behavior of concrete box-girder highway bridges. Two different finite element analyses, one stage and construction stage, have been carried out on Komurhan Bridge between Elazığ and Malatya province of Turkey, over Fırat River. The one stage analysis assume that structure was built in a second and material properties of structure not change under different loads and site conditions during time. However, construction stage analysis considers that construction time and time dependent material properties. The main and side spans of bridge are 135 m and 76 m, respectively. The bridge had been constructed in 3 years between 1983 and 1986 by balanced cantilever construction method. The parameters of soil-structure interaction (SSI), time dependent material properties and construction method are taken into consideration in the construction stage analysis while SSI is single parameter taking into consideration in the one stage analysis. The 3D finite element model of bridge is created the commercial program of SAP2000. Time dependent material properties are elasticity modulus, creep and shrinkage for concrete and relaxation for steel. Soft, medium, and firm soils are selected for evaluating SSI in both analyses. The results of two different finite element analyses are compared with each other. It is seen that both construction stage and SSI have a remarkable effect on the structural behavior of the bridge.

Earthquake response of isolated cable-stayed bridges under spatially varying ground motions

Sevket Ates,Kurtulus Soyluk,A. Aydin Dumanoglu,Alemdar Bayraktar 국제구조공학회 2009 Structural Engineering and Mechanics, An Int'l Jou Vol.31 No.6

A comprehensive investigation of the stochastic response of an isolated cable-stayed bridge subjected to spatially varying earthquake ground motion is performed. In this study, the Jindo Bridge built in South Korea is chosen as a numerical example. The bridge deck is assumed to be continuous from one end to the other end. The vertical movement of the stiffening girder is restrained and freedom of rotational movement on the transverse axis is provided for all piers and abutments. The longitudinal restraint is provided at the mainland pier. The A-frame towers are fixed at the base. To implement the base isolation procedure, the double concave friction pendulum bearings are placed at each of the four support points of the deck. Thus, the deck of the cable-stayed bridge is isolated from the towers using the double concave friction pendulum bearings which are sliding devices that utilize two spherical concave surfaces. The spatially varying earthquake ground motion is characterized by the incoherence and wavepassage effects. Mean of maximum response values obtained from the spatially varying earthquake ground motion case are compared for the isolated and non-isolated bridge models. It is pointed out that the base isolation of the considered cable-stayed bridge model subjected to the spatially varying earthquake ground motion significantly underestimates the deck and the tower responses.