Stationary and Mobile Target Detection using Mobile Wireless Sensor Networks

In this work, we study the target detection and tracking problem in mobile sensor networks, where the performance metrics of interest are probability of detection and tracking coverage, when the target can be stationary or mobile and its duration is finite. We propose a physical coverage-based mobility model, where the mobile sensor nodes move such that the overlap between the covered areas by different mobile nodes is small. It is shown that for stationary target scenario the proposed mobility model can achieve a desired detection probability with a significantly lower number of mobile nodes especially when the detection requirements are highly stringent. Similarly, when the target is mobile the coverage-based mobility model produces a consistently higher detection probability compared to other models under investigation.Comment: 7 pages, 12 figures, appeared in INFOCOM 201

The role of Sox2 in inner ear development

The vertebrate inner ear is a structurally complex sensory organ responsible for detecting sound and maintaining balance. These functions are mediated by specialized sensory epithelia comprised of a mosaic of mechano-transducing hair cells and supporting cells. The sensory hair cells are innervated by neurons of the cochleo-vestibular ganglion (CVG, the VIIIth cranial nerve). Both neuronal and sensory lineages are thought to be specified early in the neural-sensory competent domain (NSD) of the ear rudiment. First, neuroblasts delaminate from the NSD to form neurons of the CVG. Then, cells remaining in the NSD adopt a sensory fate and develop into various sensory organs. The molecular mechanisms that specify neuronal and sensory cell fates are unclear. The aim of this dissertation is to provide a better understanding by examining the roles of the HMG (high mobility group)-box containing transcription factors Sox2 and Sox3 in developing chicken inner ears using gain and loss-of-function approaches. Over-expression of Sox2 in ovo readily induces Neurogenin 1(Ngn1) expression, an important gene required for the neurogenic fate. Nevertheless, neurogenesis fails to proceed based on the lack of Neurod1 up-regulation and consequently the size of the CVG is reduced. In contrast, over-expression of Ngn1 is capable of up-regulating Neurod1 and causes increased neuroblast formation, as well as Sox2 down-regulation. Similar increases in neurogenesis are obtained with over-expression of Neurod1. I provide evidence that Ngn1 and Neurod1 inhibit Sox2 transcription via the E-box of the nasal-otic placode specific enhancer 1 (NOP-1) within the Sox2 promoter. On the other hand, loss of Sox2 function paradigms did not result in loss of Ngn1 expression, suggesting that other factors may be required to induce Ngn1 normally. Furthermore, while Sox3 has been proposed to be up-stream of Sox2, it does not induce Ngn1 in a similar manner as Sox2. Taken together, my results suggest that Sox2 and likely other factors are involved in initiating neurogenesis by up-regulating Ngn1. The up-regulated Ngn1, in turn, down-regulates Sox2 expression and up-regulates Neurod1 to mediate progression of neurogenesis. Finally, I show that Sox2 and the Notch signaling pathway interact to specify neuronal and sensory cell fate choices

Fonetik açıdan Kur'ân i'câzı

Bu çalışmayı nazil olduğu günden itibaren insanların bir benzerini meydana getirmekten âciz kaldığı Kur'ân lafızlarındaki ses ve anlam uyumu üzerine temellendirdik. Kur'ân'ın kendi içindeki bütünlüğünü müzikal yönden ön plana çıkarmak istedik. Böylece Kur'ân'ın i'câz yönlerinden sayılan bu konu ile çalışmamızı hazırladık. Çalışmada öncelikle Fonetik ilminin ne olduğu ve insanın konuşma vasfının ayrıcalığına dikkat çekildi. Fonetik tarihi farklı yönleriyle ve Arapça kaynaklar esas alınarak sunuldu. Arapça dil bilgisi ile ilgili birbirinden farklı ilimlerden, hikmet, felsefe, tıp, mûsikî yönüyle; kıraat, tecvid gibi farklı gruplar ile fonetiğin zengin yönüne dikkat çekilerek bu çalışma zeminiyle tezi inşâ etmeye çalıştık. Kur'ân'ın i'câz yönlerini genel olarak değerlendirip husûsen Beyân yönüyle Kur'ân fonetiğine dair bilgiler ve örnek ayetler üzerinde durduk. Tezin sunumunda Fonetik ile ilgili bazı sanatların Kur'ân'daki bu özel okuyuş biçimleriyle, sesteki intizâmın ilâhi kaynaklı ve mûcizevî tesirinin vurgulanışına tanık olduk. Özellikle Kur'ân'ın psikolojik etkisi üzerine söylenmiş bilgi ve kaynakları göstererek modern çalışmalara yönelik örnek çalışmalara ulaştıkça Kur'ân ile ilgili bu alandaki çalışmalara ihtiyacı fark ettik. Kur'ân'ın müzikal boyutu ile çalışmanın esas mecrâsını oluşturduktan sonra Kur'ân'ın müzikal yapısının bir kısım iç dinamiklerini yakalamaya çalıştık. Fonetik Orkestrasyon gibi konular ile de Kur'ân sesinin muhteşemliğine tanık olarak bunu tespit için örneklere yer verdik. Tezimizde ayrıca Kelâm ilmi aracılığıyla Allah'ın konuşma keyfiyetini tefekkür edip Allah'ın insana hitabını ve O'nun konuşma keyfiyetini anlayamaya çalışarak iddiamızın kaynağına ulaşmaya çalıştık

"Counting Your Customers": When will they buy next? An empirical validation of probabilistic customer base analysis models based on purchase timing

This research provides a new way to validate and compare buy-till-you-defect [BTYD] models. These models specify a customer’s transaction and defection processes in a non-contractual setting. They are typically used to identify active customers in a com- pany’s customer base and to predict the number of purchases. Surprisingly, the literature shows that models with quite different assumptions tend to have a similar predictive performance. We show that BTYD models can also be used to predict the timing of the next purchase. Such predictions are managerially relevant as they enable managers to choose appropriate promotion strategies to improve revenues. Moreover, the predictive performance on the purchase timing can be more informative on the relative quality of BTYD models. For each of the established models, we discuss the prediction of the purchase timing. Next, we compare these models across three datasets on the predictive performance on the purchase timing as well as purchase frequency. We show that while the Pareto/NBD and its Hierarchical Bayes extension [HB] models perform the best in predicting transaction frequency, the PDO and HB models predict transaction timing more accurately. Furthermore, we find that differences in a model’s predictive performance across datasets can be explained by the correlation between behavioral parameters and the proportion of customers without repeat purchases

Evidence disclosure and severity of punishments

The relationship between legal offenses and punishment is well studied by scholars of sociology, economics and law. Economists contend that punishment is a cost of committing an offense, hence an increase in the severity of punishments should decrease incentives to commit legal offenses. And the efficiency of legal punishments are studied generally from this perspective: giving efficient incentives to commit legal offense. This paper studies the relationship between punishment and evidence disclosure in a game theoretical model. A defendant is trying to persuade a judge by presenting evidence to take a favorable legal action rather than less favorable ones on his case. I show that the equilibrium disclosure of the defendant is not affected by a change in the scale of legal actions when there is no uncertainty on how the judge evaluates evidence. With uncertainty, however, the defendant can be induced to disclose more information by decreasing the severity ratio of the most unfavorable legal action to the most favorable one. This shows that in the more realistic case of uncertainty the severity of punishments has an effect on evidence disclosure and efficiency of punishment schedule should be analyzed by internalizing its effect on evidence disclosure as well

Evidence disclosure and severity of punishments

The relationship between legal offenses and punishment is well studied by scholars of sociology, economics and law. Economists contend that punishment is a cost of committing an offense, hence an increase in the severity of punishments should decrease incentives to commit legal offenses. And the efficiency of legal punishments are studied generally from this perspective: giving efficient incentives to commit legal offense. This paper studies the relationship between punishment and evidence disclosure in a game theoretical model. A defendant is trying to persuade a judge by presenting evidence to take a favorable legal action rather than less favorable ones on his case. I show that the equilibrium disclosure of the defendant is not affected by a change in the scale of legal actions when there is no uncertainty on how the judge evaluates evidence. With uncertainty, however, the defendant can be induced to disclose more information by decreasing the severity ratio of the most unfavorable legal action to the most favorable one. This shows that in the more realistic case of uncertainty the severity of punishments has an effect on evidence disclosure and efficiency of punishment schedule should be analyzed by internalizing its effect on evidence disclosure as well

Bridging Models and Business: Understanding heterogeneity in hidden drivers of customer purchase behavior

__Abstract__ Recent years have seen many advances in quantitative models in the marketing literature. Even though these advances enable model building for a better understanding of customer purchase behavior and customer heterogeneity such that firms develop optimal targeting and pricing strategies, it has been observed that not many of the advanced models have found their way into business practice. This thesis aims to bridge the gap between advanced models and their business applications by systematically extending the use of models. We first focus on probabilistic customer base analysis models that deal with understanding customer heterogeneity and predicting customer behavior. These models specify a customer's transaction and defection processes under a non-contractual setting. Through this study, we show that the timing of the next purchase for each customer can be predicted using these models. We also extend them by modeling customer heterogeneity in a more flexible and insightful way. As a result, managers can obtain a refined segmentation. Based on the customer heterogeneity insights, we then focus on pricing strategies for online retailers who derive their revenues from delivery fees and sales. In order to come up with optimal pricing strategies for delivery fees, we use ideas from the two-part tariff literature. Given the time and costs associated with implementing advanced models/theories in managerial practice, the marketing executives need to be convinced by clearly demonstrating the contributions of such models. Our study serves as a step toward bridging advanced models and business practice by empirically demonstrating their extended contributions

Balık yağı kullanılarak obezite oluşturulan ratlarda nikotin ve zencefilin antiobezite etkisinin belirlenmesi

Obesity is a disorder of energy metabolism that can cause mental and physical problems caused by excessive fat storage in the body. In this study; We aimed to determine the role of fish oil in the formation of obesity and the effects of ginger and nicotine as an antiobesity agent within complementary and alternative medicine (CAM). This study, includes 23 male rats and the groups were performed like this; Group 1 as the control (n=4), Group 2 performing experimental obesity with fish oil (n=19), Group 2a the control group (n=3, no treatment), for treatment; Group 2b the ginger applying (n=8), Group 2c the nicotine applying (n=8). In the study, weights were recorded and statistical analyzes were performed to determine the effects of obesity formation and antiobesity nutrients as well as Biochemical parameters, pathological examination and genetic analysis were applied and the results were collected. According to results, weight gain has increased in fish oil application but this gain was not found significantly important. Feeding with fish oil does not produce the expected fat and the accumulation of glycogen. In the treatment; ginger has been observed to be pathologically more effective than nicotine by removing glycogen accumulation and acting antiobesitic. Experimentally, the administration of fish oil in the obesity rat model didn’give expected weight gain. Fish oil application seems to be beneficial in terms of fatty acids consuming for health. On the contrary; the statistically significant effect of ginger, leading to more weight loss, in the anti-obesity treatment was observed.Obezite, vücutta aşırı yağ depolanması nedeniyle oluşan zihinsel ve fiziksel sorunlara neden olabilecek bir enerji metabolizması bozukluğudur. Son yıllarda, beslenme alışkanlığındaki yanlışlar sebebi ile şişmanlık insidansı artmıştır. Bu çalışmada; Balık yağının obezite oluşumundaki rolünü ve zencefil ve nikotinin bir antiobesite ajanı olarak tamamlayıcı ve alternatif tıpta (CAM) işlev ve etkilerini belirlemeyi amaçladık. Bu çalışmada 23 erkek rat kullanılmış ve gruplar şu şekildedir; Kontrol grubu olarak Grup 1 (n = 4), balık yağı ile deneysel obezite yapan Grup 2 (n = 19), grup 2a kontrol grubu (n = 3, tedavi yok), zencefil uygulayan tedavide Grup 2b (n = 8), Grup 2c nikotin uygulayarak (n = 8). Çalışmada besleme süresince tartımlar yapılarak kaydedilmiş ve obezite oluşumu ile antiobesite amaçlı olarak verilen besinlerin etkisini belirlemek üzere istatistiksel analizler ile biyokimyasal parametreler (The total kolesterol, triglycerides, LDL ve HDL kolesterol), patolojik inceleme (karaciğer ve böbrekte) ve genetik analiz (leptin sentezi) uygulanarak sonuçlar toplanmıştır. Elde edilen sonuçlara göre balık yağı uygulamasında kilo alımının kontrole kıyasla arttığı ancak bu kazancın anlamlı derecede önemli olmadığı bulunmuştur. Balık yağı ile besleme beklenen yağlanmayı oluşturmadığı gibi obezitenin öncü göstergesi kabul edilen glikojen birikimi de dokularda yeterince görülmemiştir. Tedavide; Zencefilin, glikojen birikimini kaldırarak ve antiobesitik olarak etki göstererek, nikotinden patolojik olarak daha etkili olduğu gözlenmiştir. Deneysel olarak, obezite sıçan modelinde balık yağı uygulaması beklenen kilo alımını vermedi. Balık yağı uygulamasının sağlık için tüketilen yağ asitleri açısından yararlı olduğu görülmektedir. Tam aksine; Zencefilin istatistiksel olarak anlamlı etkisinin, obezite tedavisinde daha fazla kilo kaybına neden olduğu görülmüştür

The Need for Market Segmentation in Buy-Till-You-Defect Models

Buy-till-you-defect [BTYD] models are built for companies operating in a non- contractual setting to predict customers’ transaction frequency, amount and timing as well as customer lifetime. These models tend to perform well, although they often predict unrealistically long lifetimes for a substantial fraction of the customer base. This obvious lack of face validity limits the adoption of these models by practitioners. Moreover, it highlights a flaw in these models. Based on a simulation study and an empirical analysis of different datasets, we argue that such long lifetime predictions can result from the existence of multiple segments in the customer base. In most cases there are at least two segments: one consisting of customers who purchase the service or product only a few times and the other of those who are frequent purchasers. Customer heterogeneity modeling in the current BTYD models is insufficient to account for such segments, thereby producing unrealistic lifetime predictions. We present an extension over the current BTYD models to address the extreme lifetime prediction issue where we allow for segments within the customer base. More specifically, we consider a mixture of log-normals distribution to capture the heterogeneity across customers. Our model can be seen as a variant of the hierarchical Bayes [HB] Pareto/NBD model. In addition, the proposed model allows us to relate segment membership as well as within segment customer heterogeneity to selected customer characteristics. Our model, therefore, also increases the explanatory power of BTYD models to a great extent. We are now able to evaluate the impact of customers’ characteristics on the membership probabilities of different segments. This allows, for example, one to a-priori predict which customers are likely to become frequent purchasers. The proposed model is compared against the benchmark Pareto/NBD model (Schmittlein, Morrison, and Colombo 1987) and its HB extension (Abe 2009) on simulated datasets as well as on a real dataset from a large grocery e-retailer in a Western European country. Our BTYD model indeed provides a useful customer segmentation that allows managers to draw conclusions on how customers’ purchase and defection behavior are associated with their shopping characteristics such as basket size and the delivery fee paid

DETERMINATION OF ATTITUDE AND STRESS LEVELS OF MIDWIVES, NURSES AND PHYSICIANS WORKING IN OBSTETRICS AND GYNECOLOGY CLINICS REGARDING COVID-19 PANDEMIC

Background: This study aimed to determine the attitude and stress levels of midwives, nurses and physicians working in gynecology and obstetrics clinics towards the COVID-19 pandemic. Subjects and methods: This descriptive and cross-sectional study was conducted with 134 healthcare workers in obstetrics and gynecology clinics. The Personal Information Form, the Attitude form for the COVID-19 pandemic and the Perceived Stress Scale were used for collecting the data. Results: It was found that the total average score of the healthcare workers\u27 attitude scale was 55.61+-5.97. The total score average of healthcare workers on the perceived stress scale was found to be 28.28+-7.43. Conclusion: It was determined that the attitudes of healthcare professionals towards the COVID-19 pandemic and the perceived stress for the COVID-19 pandemic were at moderate levels