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Effect of Soil-Structure Interaction on the Seismic Response of Existing Low and Mid-Rise RC Buildings
No full textReconnaissance studies performed after destructive earthquakes have shown that seismic performance of existing buildings, especially constructed on weak soils, is significantly low. This situation implies the negative effects of soil-structure interaction on the seismic performance of buildings. In order to investigate these effects, 40 existing buildings from Turkey were selected and nonlinear models were constructed by considering fixed-base and stiff, moderate and soft soil conditions. Buildings designed before and after Turkish Earthquake code of 1998 were grouped as old and new buildings, respectively. Different soil conditions classified according to shear wave velocities were reflected by using substructure method. Inelastic deformation demands were obtained by using nonlinear time history analysis and 20 real acceleration records selected from major earthquakes were used. The results have shown that soil-structure interaction, especially in soft soil cases, significantly affects the seismic response of old buildings. The most significant increase in drift demands occurred in first stories and the results corresponding to fixed-base, stiff and moderate cases are closer to each other with respect to soft soil cases. Distribution of results has indicated that effect of soil-structure interaction on the seismic performance of new buildings is limited with respect to old buildings
COVID-19 Küresel Salgını ve Yapay Zekâ Çalışmaları
No full textCOVID-19 Küresel Salgını ve Yapay Zekâ Çalışmalar
Shaping of Flexibility in Urban Renewal Legal Sources in Turkey and Its Effect on Practices
No full textPurpose: Discussions in planning systems of different countries under the influence of structural changes at the macro level are concentrated around flexibility and certainty. Since 2000, Turkey have triggered a shift in the planning system which is defined as regulatory in theory, towards a more flexible system in practice. This flexible system can be also seen in urban renewal practices. The aim of the article is to discuss the flexibility shaped by the legal sources with examples of urban renewal in Turkey.Design/Methodology/Approach:As methodology, in the study, firstly, international and national literature on flexibility in planning systems was investigated. Afterwards, shaping flexibility in planning systems is focused on three categories; (1) spatial planning, (2) property rights, and (3) discretionary power. Legal sources related to urban renewal areas, and their practices are examined under three categories based on findings of some examples in literature. Findings:The findings demonstrate that the increase in the degree of flexibility directly affects the spatial planning, property rights, and using of the discretionary power: Firstly, the scope and power of spatial plans are eliminated. Secondly, the property right, which is protected by the constitution, is ignored. Thirdly, since the limits of discretionary power are not clear, the outcomes of practices cannot be controlled either.Research Limitations/Implications:The study based on findings of some examples in literature. In the study, no specific area study has been conducted.Social/Practical Implications:As a result of these study, laws and regulations related to urban renewal can be rearranged in terms of property rights, discretion power and spatial planning. Thus, more livable cities can be created with the participation of people in urban renewal practices and the public benefit of planning.Originality/Value:There are quite limited studies focus on shaping of flexibility, and its effects in urban renewal. The originality of this study is to examine the shaping of flexibility in legal sources related to urban renewal, and reflections into the practices
Automated segmentation of the injured kidney due to abdominal trauma
No full textTulum, Gökalp (Arel Author) Osman, Onur (Arel Author)The objective of this study is to propose and validate a computer-aided segmentation system which performs the automated segmentation of injured kidney in the presence of contusion, peri-, intra-, sub-capsular hematoma, laceration, active extravasation and urine leak due to abdominal trauma. In the present study, total multi-phase CT scans of thirty-seven cases were used; seventeen of them for the development of the method and twenty of them for the validation of the method. The proposed algorithm contains three steps: determination of the kidney mask using Circular Hough Transform, segmentation of the renal parenchyma of the kidney applying the symmetry property to the histogram, and estimation of the kidney volume. The results of the proposed method were compared using various metrics. The kidney quantification led to 92.3 +/- 4.2% Dice coefficient, 92.8 +/- 7.4%/92.3 +/- 5.1% precision/sensitivity, 1.4 +/- 0.6 mm/2.0 +/- 1.0 mm average surface distance/root-mean-squared error for intact and 87.3 +/- 8.4% Dice coefficient, 84.3 +/- 13.8%/92.2 +/- 3.8% precision/sensitivity and 2.4 +/- 2.2 mm/4.0 +/- 4.2 mm average surface distance/root-mean-squared error for injured kidneys. The segmentation of the injured kidney was satisfactorily performed in all cases. This method may lead to the automated detection of renal lesions due to abdominal trauma and estimate the intraperitoneal blood amount, which is vital for trauma patients
Observation of the decays chi(cJ) -> phi phi eta
No full textUsing a data sample of (448.1 +/- 2.9) x 10( )(6)psi(3686) decays collected by the BESIII detector at the Beijing Electron Positron Collider (BEPCII), we observe the decays chi(cJ) -> phi phi eta (J = 0, 1, 2), where the chi(cJ) are produced via the radiative processes psi(3686) -> gamma chi(cJ) . The branching fractions are measured to be B(chi(c0) -> phi phi eta) = (8.41 +/- 0.74 +/- 0.62) x 10(-4), B(chi(c1) -> phi phi eta) = (2.96 +/- 0.43 +/- 0.22) x 10(-4), and B( chi(c2) -> phi phi eta) = (5.33 +/- 0.52 +/- 0.39) x 10(-4), where the first uncertainties are statistical, and the second are systematic. We also search for intermediate states in the phi phi or eta phi subsystems, but no significant structure is seen due to the limited statistics
The long-term impacts of preterm birth and associated morbidities on bone health in preschool children: a prospective cross-sectional study from Turkey
No full textObjective: To evaluate the impact of preterm birth on bone health in preschool children. Methods: A total of 166 preschool children (aged 7-8 years) born preterm (n = 86, = 37 weeks of gestation) in our hospital were included in this prospective cross-sectional study. Data on antenatal, perinatal, and early postnatal characteristics and maternal obstetric history were obtained from medical records. Bone densitometry data including total bone mineral content (BMC), bone mineral density (BMD; total, lumbar, and femoral), z-scores, and bone loss were collected for each participant. Results: Current height, weight, and BMI values were significantly lower in the preterm group (p < .001). Serum calcium, phosphorus and alkaline phosphatase (ALP) levels did not differ among groups, whereas VitD3 levels were significantly higher in the preterm group (p = .039). The mean total BMC, total BMD, lumbar (L2-L4) BMD, femur BMD, total z-score, and L2-L4 z-score values were significantly lower for the preterm group, whereas the total, lumbar, and femoral bone loss were significantly higher (p < .001), regardless of the severity of prematurity. Intraventricular hemorrhage (IVH) and retinopathy were significantly associated with lower total BMC (p = .004, p = .012, respectively). Fortified breastfeeding was associated with lumbar bone loss (p = .043), and formula feeding was associated with both femur and lumbar bone loss (p = .006, p = .012, respectively). Conclusions: Our findings revealed long-term adverse effects of preterm birth on bone health, with significantly lower anthropometric values (weight, height, and BMI), lower scores for total BMC, BMD (total, lumbar, femoral), and z-scores (total, femur), along with higher bone loss (total, lumbar, femoral) and higher rates of osteopenia and osteoporosis in preschool children born preterm (whether moderate or very preterm) compared with those born at term. Exclusive breastfeeding appears to reduce the likelihood of long-term bone loss in preterm infant
Measurement of the Cross Section for e(+)e(-) -> Xi(-)Xi(+)and Observation of an Excited Xi Baryon
No full textUsing a total of 11.0 fb(-1) of e(+)e(-) collision data with center-of-mass energies between 4.009 and 4.6 GeV and collected with the BESIII detector at BEPCII, we measure fifteen exclusive cross sections and effective form factors for the process e(+)e(-) -> Xi(-)Xi(+) by means of a single baryon-tag method. After performing a fit to the dressed cross section of e(+)e(-)-> Xi(-)Xi(+) no significant psi(4230) or psi(4260) resonance is observed in the Xi(-)Xi(+) final states, and upper limits at the 90% confidence level on T B-ee for the processes psi(4230)psi/(4260) -> Xi(-)Xi(+) are determined. In addition, an excited Xi baryon at 1820 MeV/c(2) is observed with a statistical significance of 6.2-6.5 sigma by including the systematic uncertainty, and the mass and width are measured to be M = (1825.5 +/- 4.7 +/- 4.7) MeV/c(2) and Gamma = (17.0 +/- 15.0 +/- 7.9) MeV, which confirms the existence of the J(P) =3-/2 state Xi (1820)