Effects of Covid-19 lockdowns on social distancing in Turkey

This paper elucidates the causal effect of lockdowns on social distancing behaviour in Turkey by adopting an augmented synthetic control and a factor-augmented model approach for imputing counterfactuals. By constructing a synthetic control group that reproduces pre-lockdown trajectory of mobility of the treated provinces and that accommodates staggered adoption, the difference between the counterfactual and actual mobility of treated provinces is assessed in the post-lockdown period. The analysis shows that in the short run following the onset of lockdowns, outdoor mobility would have been about 17–53 percentage points higher on average in the absence of lockdowns, depending on social distancing measure. However, residential mobility would have been about 12 percentage points lower in the absence of lockdowns. The findings are corroborated using interactive fixed effects and matrix completion counterfactuals that accommodate staggered adoption and treatment reversals.WOS:000839532700001Science Citation Index Expanded - Social Sciences Citation IndexQ2Article; Early AccessUluslararası işbirliği ile yapılmayan - HAYIRAugust2022YÖK - 2021-22Ağusto

Design of a Mars Rover suspension mechanism

Thesis (Master)--Izmir Institute of Technology, Mechanical Engineering, Izmir, 2004Includes bibliographical references (leaves: 71-75)xiii, 75 leavesIt is obvious that rovers are important vehicles of today.s solar system exploration. Most of the rover designs have been developed for Mars and Moon surface in order to understand the geological history of the soil and rocks. Exploration operations need high speed and long distance traversal in a short mission period due to environmental effects, climate and communication restrictions. Several mechanisms have been suggested in recent years for suspensions of rovers on rough terrain. Although their different mechanisms have found a widespread usage in mobile robotics, their low operation speed is still a challenging problem. In this research, a new suspension mechanism has been designed and its kinematic analysis results were discussed. Standard rocker-bogie suspension mechanism, which has been developed in the late 1990.s, has excellent weight distribution for different positions on rough terrain. New design, mostly similar to rocker-bogie suspension system, has a natural advantage with linear bogie motion which protects the whole system from getting rollover during high speed operations. This improvement increases the reliability of structure on field operations and also enables the higher speed exploration with same obstacle height capacity as rocker-bogie. In this thesis study, new bogie mechanism consisted of double-lambda mechanisms, which has been firstly presented by Pafnuty Lvovich Chebyshev in 1869, is solved by analytically to define the positions and singular configurations. A new structural synthesis formula also has been introduced for such suspension mechanisms with lower and higher kinematic pairs. By using structural synthesis methods, a suspension mechanism has been designed with double-lambda mechanism. Equivalent force and moment functions were also derived with equation of motion method. The results are confirmed with the computer analysis made by Visual Nastran 4D®. For this purpose, a computer model has been constructed and assembled with the same design parameters of NASA Mars Exploration Rovers (MER1 and MER2)

Licensing of a drastic innovation with product differentiation

We analyze the licensing of a drastic innovation when products are differentiated due to consumer and/or product heterogeneity. We show that an industry insider prefers to divest its production arm and license the new technology as an industry outsider, in which case it can replicate multiproduct monopoly profits. We derive the optimal contracts and the optimal number of licenses by assuming a logit demand system. Optimal number of licenses, quite strikingly, increases when the technology has a higher relative value than a commercialized alternative. This result stands in sharp contrast with the literature on the licensing of a homogenous good

The foreign tourist's perceptions about the psychological pricing practices in food and beverage establishments: A study on British tourists

İşletmeler, pazardaki durumlarını korumak ve pazar paylarını artırmak için pazarlamaya dayalı çeşitli stratejilerle tüketicileri etkilemek istemektedirler. İşletmeler açısından özellikle ürün fiyatlarıyla ilgili stratejiler bu noktada önem kazanmaktadır. Çünkü fiyatlar işletme ve ürünle ilgili yeterli bilgilerin olmadığı zamanlarda tüketici algılamalarını etkileyen bir unsur olmaktadır. Bilindiği gibi yiyecek-içecek hizmet ürünleri somut özelliklerinin yanında personelin ilgisi, işletmenin tasarımı, dekoru, atmosferi vs. birçok özellikten etkilenen ve tüketicilerin ancak faydalandıkları zaman tam olarak bilgi sahibi olacakları ürünler olmaktadır. Yiyecek-içecek hizmet ürünlerinin soyut karakterli olmasıyla beraber fiyatların işletme ve ürün ile ilgili tüketici algılamaları üstündeki etkisi de düşünüldüğünde yiyecek-içecek işletmeleri için fiyat temelli stratejilerinin neden önemli olduğu anlaşılacaktır. Bu açıdan; günümüz sıkı rekabet ortamında fiyatların tüketici algılamaları üstündeki etkilerinden hareketle geliştirilen psikolojik fiyat stratejilerinin yiyecek-içecek işletmelerinde kullanılması gerekliliği söz konusu olmaktadır. Bu çalışmada; yiyecek-içecek işletmelerinde psikolojik fiyat stratejileri ayrıntılarıyla açıklanmaya ve psikolojik fiyat stratejilerinin yiyecek-içecek işletmelerinde tüketici satınalma davranışı unsurları açısından yeri ortaya konulmaya çalışılmıştır. Bu amaçla; yiyecek içecek işletmelerinde psikolojik fiyat uygulamalarının yabancı turist algılamaları üstündeki etkisi de incelenerek yiyecek ve içecek işletmelerine psikolojik fiyat uygulamaları hakkında somut bilgiler sunulmak istenmiştir.In order to maintain their market share and to increase their market, establishments are in the pursuit of influencing the customers through some strategies based on marketing. Strategies on pricing gain importance for establishments, for prices are of great factors that affect the perception of customers when there is no enough information on the establishments and the product. As it is known, food and beverage service products are the ones that are affected by the interests of the staff, design, atmosphere and the ambience of the establishment only when the customers can get insight and information into the nature of the product on benefiting from the product besides their tangible nature. The products of food and beverage aside from their intangible nature and considering the effect of the price on the perception of the customers, the importance of price-based strategies will be understood. In this regard, in the fierce competitive environment, psychological pricing strategies developed out of the effect of pricing on the perception of customers will be required to be used in food and beverage establishments. This study aims to put forward position of psychological pricing strategies in terms of behavior of consumer purchasing in food and beverage establishment and to explain the strategies of psychological pricing strategies in detail. To serve his purpose, the effect of psychological pricing strategies on foreign tourists will be examined and concrete findings which were obtained through this study will be tried to be presented

Effects of contemporary orthodontic composites on tooth color following short-term fixed orthodontic treatment: A controlled clinical study

Background/aim: To determine the color alterations of natural teeth associated with different orthodontic composites used in comprehensive short-term treatment. Materials and methods: Twenty-two patients were treated with fixed appliances and 22 untreated subjects were also evaluated. Lower incisors were bonded with different orthodontic composites: 42 with Grengloo, 41 with Light Bond, 31 with Kurasper F, and 32 with Transbond XT. The color parameters of the Commission Internationale de l’Eclairage (CIE) were measured for each tooth with a spectrophotometer. Color assessment in relation to time, adhesive material, and their interaction was made with 2-way mixed analysis of variance (ANOVA) and 1-way ANOVA for the color differences (ΔE*). Further analyses were done using Tukey’s honestly significant difference tests and paired-samples t-tests. Results: The color of teeth was affected by treatment. The mean L* and a* values increased, whereas the mean b* values decreased. Total color differences of teeth demonstrated visible color changes clinically after treatment, ranging from 1.12 to 3.34 ΔE units. However, there were no significant differences for color of enamel. Conclusion: Teeth may be discolored with fixed appliances during treatment. Moreover, contemporary orthodontic composites have similar effects of enamel discoloration. © TÜBİTAK

Prevalance of malassezia agents in dogs with dermatoses

Bu çalışmada sağlıklı ve dermatozlu köpeklerde Malassezia etkenlerinin prevalansı, bölgesel dağılımı ve örnek alınan bölgeler arasındaki ilişkinin ortaya çıkarılması amaçlandı. Farklı ırk ve cinsiyetteki toplam 150 adet (100 dermatozlu, 50 sağlıklı) köpekten sistematik olarak 7 farklı anatomik bölgeden sitoloji için nemlendirilmiş steril pamuk svaplar aracılığıyla örnek alındı. Alınan örneklerin her biri May-Grunwald Giemsa boyası ile boyandı. Toplanan örnekler mikroskopta 40'lık büyütmede incelendi ve inceleme sonucunda örneklerde Malassezia etkenlerinin sitolojik tanısı ve popülasyon büyüklüğü belirlendi. İnceleme sonucunda rastgele seçilen 5 alanda 10 veya daha fazla Malassezia etkeninin görülmesi pozitif olarak kabul edilirken, 10'dan daha az Malassezia etkeninin görülmesi ise negatif olarak değerlendirildi. Köpeklerden elde edilen sonuçlar SPSS paket programında x2 testi kullanılarak istatistiksel açıdan değerlendirildi. Sağlıklı ve dermatozlu hayvanlar arasında periorbital, perioral, dış kulak, inguinal ve perianal bölgeler arasında istatistiksel yönden önem bulunurken, boynun dorsali ve interdigital bölgeler arasında istatistiksel yönden önem bulunamadı. Sonuç olarak, pozitif Malassezia görülme oranının sağlıklı köpeklerde en sıklıkla perianal bölgede, dermatozlu köpeklerde ise perioral bölgede olduğu ve hayvanın kendisini sürekli yalaması ve kaşımasıyla bağlantılı olarak anal bölgenin sağlıklı köpeklerde Malassezia etkenleri yönünden taşıyıcı, perioral bölgenin dermatozlu köpekler açısından bulaştırıcı rolünün olduğu ortaya kondu.In this study, the aim was to expose the interactions between prevalence, regional distribution and exemplary locations of Malessezia agents among healthy dogs and dogs with dermatoses. In an attempt to perform cytology moistened sterile cotton swap samples were systematically withdrawn from 7 different anatomical regions, from a total of 150 (100 with dermatoses, 50 healthy) dogs, of various breed and of both sexes, for cytology. Each of the samples withdrawn were stained with May-Grunwald Giemsa dye. Evaluated samples were examined under 40x microscope magnification and consequently cytological diagnosis of samples and population size of Malassezia factors were determined. As a result of examination in randomly selected 5 fields of 10 or more on factors of Malassezia were regarded as positivity, whereas less than 10 of Malassezia observation were regarded as negative. The results obtained from the dogs were evaluated by use of x2 test within SPSS statistical package program in terms. A Statistical significance was found among healthy dogs and dogs with dermatoses regarding periorbital, perioral, outer ear, inguinal and perianal regions whereas the dorsal aspect of the neck and interdigital locations did not reveal statistical significance. As a result, it was concluded that the rate of positive Malassezia observation in healthy dogs and dogs with dermatoses was frequently ivolved perianal region and the perioral region, respectively, and in association with the animal itself constantly licking and scratching behaviour the anal area is in a carrier status in terms of factors of Malassezia in healthy dogs, and perioral region has a contagious role in terms of infection in dogs with dermatoses

Welfare improving product bans

We formulate a model of vertical differentiation to evaluate the welfare effects of removing a low quality product from the market. The mechanism through which a welfare improvement might arise is simple: Once the low quality low cost alternative is banned, entry into the high quality segment becomes more likely. This in turn may lead to a significant reduction in the price of the high quality product. We find that such a ban might improve aggregate welfare when consumers value the higher quality more, the marginal cost of producing high quality is lower, the price of low quality is higher, and the price sensitivity for high quality is not too high