Price Setting Behavior in Turkish Industries: Evidence From Survey Data

This study investigates the price setting behavior of Turkish industries based on the results of a survey that was conducted by the Central Bank of the Republic of Turkey. The results show that under normal conditions, the majority of the firms follow time-dependent pricing rule but when significant events occur substantial fraction of them alter their behavior to state dependent reviewing. The median Turkish firm reviews its prices every month, but changes its prices four times a year. Price reviews and changes are affected by: the market share, price discrimination, customer type, firm size and the existence of regulated prices.price-setting, price-rigidity, survey

Effect of COVID-19 pandemic on glaucoma

Aim: To observe the course of glaucoma progression after coronavirus disease 2019 (COVID-19) treatment of patients with glaucoma. Methods: This observational case-control study included a total of 74 patients with COVID-19 infection who were diagnosed with glaucoma previously. The study focused on the left eye of 37 patients each was treated as an inpatient (group 1) or outpatient (group 2). Age, gender, existence of systemic and ocular diseases, symptoms, laboratory results, drugs used for COVID-19 and glaucoma, length of hospital stay, intraocular pressure (IOP), and central corneal thickness (CCT) values were recorded. Peripapillary retinal nerve fiber layer thickness (ppRNFLT), ganglion cell–inner plexiform layer complex thickness (GCIPLT), and vertical cup-disc (C-D) ratio results were compared before and after COVID-19 treatment in both groups. Results: A significant increase was observed in IOP and a significant decrease was observed in GCIPLT in both groups (groups 1 and 2 for both values p<0.01 and p=0.02, respectively) after COVID-19 infection. In both groups, the mean difference (MD) for IOP and GCIPLT values were higher in group 1. Although ppRNFLT values decreased in both groups, a significant decrease was observed in group 1 after COVID-19 infection (p=0.03). The mean C-D ratio was higher after COVID-19 infection in groups 1 and 2. (p=0.04 and p=0.051, respectively). CCT did not show a significant difference in either group (p>0.05). Conclusion: PpRNFLT and GCIPLT values were reduced and IOP and C-D ratio values were increased in glaucoma patients after COVID-19 infection. Infection progression was observed to be worse in the inpatient group.

Projections for Neutral Di-Boson and Di-Higgs Interactions at FCC-he Collider

As a high energy e-p collider, FCC-he, has been recently proposed with sufficient energy options to investigate Higgs couplings. To analyse the sensitivity on the Higgs boson couplings, we focus spesifically on the CP-even and CP-odd Wilson coefficients with $hhZZ\:$and $hh\gamma\gamma\:$ four-point interactions of Higgs boson with Effective Lagrangian Model through the process $e^{-}p\to hhje^{-}$ . We simulate the related processes in FCC-he, with 60 GeV and 120 GeV $e^{-}$ beams and 50 TeV proton beam collisions. We present the exclusion limits on these couplings both for 68% and 95% C.L. in terms of integrated luminosities.Comment: 18 pages, 20 figures, 3 table

Coexistence and Secure Communication in Wireless Networks

In a wireless system, transmitted electromagnetic waves can propagate in all directions and can be received by other users in the system. The signals received by unintended receivers pose two problems; increased interference causing lower system throughput or successful decoding of the information which removes secrecy of the communication. Radio frequency spectrum is a scarce resource and it is allocated by technologies already in use. As a result, many communication systems use the spectrum opportunistically whenever it is available in cognitive radio setting or use unlicensed bands. Hence, efficient use of spectrum by sharing users is crucial to increase maximize system throughput. In addition, secrecy of a wireless communication system is traditionally provided by computational complexity of cryptography techniques employed. However, cryptography systems depend on either a random secret key generation mechanism or a trusted key distribution system. Recent developments in the wireless communication area provided a solution to both key generation and distribution problem via exploiting randomness of the wireless channel unconditional to the computational complexity. In this dissertation, we propose solutions to the problems discussed. For spectrum sharing, we present a detailed analysis of challenges of efficient spectrum sharing without a central enforcing mechanism, provide insight to already existing power control algorithms and propose a novel non-greedy power allocation algorithm. Numerical simulations show that the proposed algorithm increases system throughput more than greedy algorithms and can use available spectrum to the fullest, yet it is robust to the presence of greedy users. For secrecy, we propose a practical and fast system for random secret key generation and reconciliation. We extend the proposed system to multiple-input-multiple-output systems and increase security via role reversal of the nodes while making it quicker by pre-encoding procedure. Information theory calculation and numerical simulations demonstrates that the proposed system provides a secure channel for legitimate users in the presence of a passive eavesdropper

Gender Differences in College Applications: Evidence from the Centralized System in Turkey

In Turkey, as in many other countries, female students perform better in high school and have higher test scores than males. Nevertheless, men still predominate at highly selective programs that lead to high-paying careers. The gender gap at elite schools is particularly puzzling because college admissions are based entirely on nationwide exam scores. Using detailed administrative data from the centralized college entrance system, I study the impact of gender differences in preferences for programs and schools on the allocation of students to colleges. Controlling for test score and high school attended, I find that females are more likely to apply to lower-ranking schools, whereas males set a higher bar, revealing a higher option value for re-taking the test and applying again next year. I also find that females and males value program attributes differently, with females placing more weight on the distance from home to college, and males placing more weight on program attributes that are likely to lead to better job placements. Together, these differences in willingness to be unassigned and in relative preferences for school attributes can explain much of the gender gap at the most elite programs

Using multiple visual tandem streams in audio-visual speech recognition

The method which is called the "tandem approach" in speech recognition has been shown to increase performance by using classifier posterior probabilities as observations in a hidden Markov model. We study the effect of using visual tandem features in audio-visual speech recognition using a novel setup which uses multiple classifiers to obtain multiple visual tandem features. We adopt the approach of multi-stream hidden Markov models where visual tandem features from two different classifiers are considered as additional streams in the model. It is shown in our experiments that using multiple visual tandem features improve the recognition accuracy in various noise conditions. In addition, in order to handle asynchrony between audio and visual observations, we employ coupled hidden Markov models and obtain improved performance as compared to the synchronous model