The impact of time limitation: insights from a queueing experiment

We experimentally explore the effects of time limitation on decision making. Under different time allowance conditions, subjects are presented with a queueing situation and asked to join one of the two given queues. The results can be grouped under two main categories. The first one concerns the factors driving decisions in a queueing system. Only some subjects behave consistently with rationality principles and use the relevant information efficiently. The rest of the subjects seem to adopt a simpler strategy that does not incorporate some information into their decision. The second category is related to the effects of time limitation on decision performance. A substantial proportion of the population is not affected by time limitations and shows consistent behavior throughout the treatments. On the other hand, some subjects’ performance is impaired by time limitations. More importantly, this impairment is not due to the stringency of the limitation but rather to being exposed to a time constraint

Three-dimentional reconstruction of the lentiform nucleus from serial sections in man

Three-dimensional (3-D) reconstruction of the lentiform nucleus was performed by using serial macroscopic anatomic sections, taken from a human cadaver. When the rendered form of this wire-frame reconstruction was examined, it was found that both the putamen and globus pallidus had upper and lower poles. The distances between the upper and lower poles were 2.23 cm in the putamen and 1.45 cm in the globus pallidus. The lower poles of the putamen and globus pallidus were about the same level but the upper pole of the putamen was 0.78 cm higher than in the globus pallidus. The vertical dimension of the lentiform nucleus was 22.9 mm. This is the first study reporting the three-dimensional reconstruction and the dimensions of the lentiform nucleus of the human brain. We believe that this study will be of help in future studies concerning the lentiform nucleus and its relations

Tumor or Hematoma?: An Unusual Case of an Extradural Lesion of the Lumbar Spine

Purpose: Spinal epidural hematoma is a rare clinical entity. We present a case of atypical contrast enhancement pattern in a chronic epidural hematoma of the lumbar spine mimicking an extradural tumor. Case Report: A 76-year-old man on treatment with oral anticoagulants presented with a 1-month history of lower back pain radiating into his right upper thigh accompanied by spinal claudication. Preoperative MRI showed a posterior epidural lesion compressing the cauda equina with almost homogeneous contrast enhancement. Surgery was performed under the presumptive diagnosis of spinal extradural neoplasm. Intraoperative and histological findings were consistent with a chronic spinal epidural hematoma. Postoperatively, the patient had instant relief of his symptoms. Conclusion: Chronic spinal epidural hematoma may resemble an extradural tumor, requiring surgery for histological confirmation and decompressio

Performance comparison of 802.11 and 802.16 technologies for video transmission in NS2-EvalVid [802.11 ve 802.16 teknolojilerinin video aktarim başarimlarinin NS2-EvalVid ortaminda karşilaştirmasi]

2008 IEEE 16th Signal Processing, Communication and Applications Conference, SIU -- 20 April 2008 through 22 April 2008 -- Aydin -- 74111In this study, the video transmission performances of 802.11 and 802.16 technologies are compared by using simulations. The integration of NS2 and EvalVid defined in literature is the simulation tool used in this work. 802.16 and EvalVid packets are patched in to NS2. A real video file is converted into MP4 format with preprocessing, then its transmission is simulated over NS2-EvalVid tool for both technologies. The PSNR values obtained by conducting post processing are compared. ©2008 IEEE

Detecting and tracking moving objects in real time images via active camera [Aktif kamera ile gerçek zaman görüntülerde hareketli nesnelerin bulunmasi ve takip edilmesi]

18th IEEE Signal Processing and Communications Applications Conference, SIU 2010 -- 22 April 2010 through 24 April 2010 -- Diyarbakir -- 83388In this work, moving objects tracking methods in real-time images have been examined and emphasized on active camera hardware and software. An integrated system has been build together with moving objects detecting and tracking methods, noise reduction and active camera which includes pan/tilt servo motors. Moving object tracking process is achieved by adaptation of frame difference technique on two new approaches. These approaches are namely: delayed frame difference and edge detected frame difference approaches. Frame difference processes for moving object detection are accomplished after a specific delay for the first approach and after the edge detection and matching processes for the second approach. Lastly a performance analysis has been performed on moving object tracking considering the delayed frame difference and the corner detected frame difference approaches, and the results are compared. ©2010 IEEE

Investigation of the effects of nanomaterials on radiation shielding properties of composite materials

A careful look around shows that radiation is a reality that exists in every moment of life. As a result of the widespread use of radiation rays due to developments in science, human beings are exposed to radiation much more. Avoiding exposure to radiation in the use of radiation sources is a vital issue to be considered. For this purpose, different techniques have been developed to protect from radiation. In this review, information about radiation and radiation protection methods is given and the contribution of nano-sized materials used in the production of composite materials to radiation shielding was systematically examined. © 2021, TUBITAK. All rights reserved.2-s2.0-8510108073

Evaluation of mechanical properties of Bi12SiO20 sillenite using first principles and nanoindentation

The mechanical and anisotropic elastic properties of Bi12SiO20 (BSO) were investigated using density functional theory (DFT) calculations and nanoindentation. The calculated and experimentally observed XRD patterns of the compound were reported and the crystal structure of the BSO was determined to be cubic with the lattice constant of a = 1.025 nm. The second-order elastic constants and related polycrystalline elastic moduli (e.g. shear modulus, Young's modulus, Poisson's ratio, linear compressibility and hardness) were calculated. The calculated elastic constants indicated that BSO is mechanically stable and exhibits anisotropic characteristics. Moreover, the directional dependencies of sound wave velocities were investigated in three dimensions. Pressure-dependent bulk modulus was plotted at temperatures between 0 and 800 K. Hardness and Young's modulus were also determined by performing nanoindentation experiments on (222) and (631) planes of the BSO single crystal. The analyses of the experimental nanoindentation data resulted in hardness and Young's modulus values of 7.2 and 97.0 GPa, respectively. The results of DFT and nanoindentation were discussed throughout the paper. The results of the present paper would provide valuable information on the mechanical behaviours of the BSO for the optoelectronic device applications

Liver metabolic activity changes over time with neoadjuvant therapy in locally advanced rectal cancer

Objective The aim of this study was to evaluate, using PET/computed tomography (CT), changes in liver metabolic activity in patients with locally advanced rectal cancer (LARC) after neoadjuvant chemoradiotherapy (CRT). Patients and methods A total of 29 biopsy-proven LARC patients between 2009 and 2012 were studied. Liver standardized uptake values (SUVs) and SUVs adjusted for lean body mass (SULs) were obtained from PET/CT images obtained at 1 h (early) and 2 h (late) after 18F-fluorodeoxyglucose (18F-FDG) administration both before and after neoadjuvant CRT. Age, sex, BMI, lean body mass, blood glucose level, and 18F-FDG dose, which can influence liver SUVs and SULs, were also analyzed. Results Fourteen (48%) men and 15 (52%) women with a mean age of 62±11 years (range 34-80 years) were included in the study. The mean SUVs and SULs were significantly decreased in the late scans. Sex was significantly correlated with the mean liver SUV in early and late scans. The mean SUV differed significantly between male and female patients in early and late images (P<0.05). In a multivariate stepwise regression analysis, only liver SUVs (maximum and mean) were significantly associated with BMI before and after therapy. SUVs were significantly higher in the high (≥25) BMI group after but not before therapy. Mean SUL was not influenced by BMI. Conclusion Liver 18F-FDG uptake is consistent before and after neoadjuvant CRT therapy in patients with LARC. When assessing response to therapy and using liver metabolic activity to indicate background activity, BMI should be considered as it can influence liver metabolic activity. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved

Structural, electronic, elastic, thermodynamic and vibration properties of TbN compound from first principles calculations

We have predicted structural, electronic, elastic, thermodynamic and vibration characteristics of TbN, using density functional theory within generalized-gradient (GGA) apraximation. For the total energy calculation we have used the projected augmented plane-wave (PAW) implementation of the Vienna Ab initio Simulation Package (VASP). We have used to examine structure parameter in eight different structures such as in NaCl (B1), CsCl (B2), ZB (B3), Tetragonal (L1(0)), WC (Bh), NiAs (B8), PbO (B10) and Wurtzite (B4). We have performed the thermodynamics properties for TbN by using quasi-harmonic Debye model. We have, also, predicted the temperature and pressure variation of the volume, bulk modulus, thermal expansion coefficient, heat capacities and Debye temperatures in a wide pressure (0-130 GPa) and temperature ranges (0-2000 K). Furthermore, the band structure, phonon dispersion curves and corresponding density of states are computed. Our results are compared to other theoretical and experimental works, and excellent agreement is obtained. (C) 2012 Elsevier Masson SAS. All rights reserved