On Some Properties of Tribonacci Quaternions

In this paper, we give some properties of the Tribonacci and Tribonacci-Lucas quaternions and obtain some identities for them

Describing and Forecasting Video Access Patterns

Computer systems are increasingly driven by workloads that reflect large-scale social behavior, such as rapid changes in the popularity of media items like videos. Capacity planners and system designers must plan for rapid, massive changes in workloads when such social behavior is a factor. In this paper we make two contributions intended to assist in the design and provisioning of such systems.We analyze an extensive dataset consisting of the daily access counts of hundreds of thousands of YouTube videos. In this dataset, we find that there are two types of videos: those that show rapid changes in popularity, and those that are consistently popular over long time periods. We call these two types rarely-accessed and frequently-accessed videos, respectively. We observe that most of the videos in our data set clearly fall in one of these two types. For each type of video we ask two questions: first, are there relatively simple models that can describe its daily access patterns? And second, can we use these simple models to predict the number of accesses that a video will have in the near future, as a tool for capacity planning? To answer these questions we develop two different frameworks for characterization and forecasting of access patterns. We show that for frequently-accessed videos, daily access patterns can be extracted via principal component analysis, and used efficiently for forecasting. For rarely-accessed videos, we demonstrate a clustering method that allows one to classify bursts of popularity and use those classifications for forecasting

THE EFFECT OF 8-WEEK BALL-HANDLING TRAINING PROGRAM ON UPPER-LOWER EXTREMITY MUSCULAR STRENGTH OF INDIVIDUALS WITH DOWN SYNDROME

Purpose: In this study, it has been aimed to determine the effect of 8-week ball-handling training program on upper-lower extremity muscular strength of individuals with Down syndrome.Method: In the study, twenty one individuals who had been medically diagnosed with trisomy down syndrome and still attending special education and rehabilitation centres have participated as voluntarily. The participants have been selected randomly and divided into exercise (10 participants) and control groups (11 participants). The exercise group was trained with Ball-handling Training Program for 8 weeks; 2 days a week and a 60 minute per day. However, the control group did not participate in any activities regularly. In the study, Takei hand grip dynamometer was used to measure upper extremity strength. For the measurement of lower extremity strength, standing broad jump–vertical jump, wall squat test and Takei leg dynamometer strength tests were utilized. The statistical analyses of the data were realized by using SPSS 21.0 package program.Results: The means of after eight weeks, leg strength test (pre:22.47±13.12; post:30.90±13.87; p=.005) wall squat test (pre:23.55±10.95; post:30.92±13.87; p=.005) and dominant hand grip strength (pre:11.35±5.74; post:14.55±7.18; p=.024) were found more significant than the means of baseline in exercise group. But, It was not significant differences between post measurements of exercise and control groups (p>0.05).Conclusion: The findings of the study have revealed that 8-week ball-handling training program made a positive effect on upper-lower extremity strength of individuals with Down syndrome. However, it is assumed that if the program implemented is maintained for a longer period of time, the positive effect of the training on individuals with DS will increase.  Article visualizations

Boğaziçi Yerleşmelerinden Emirgan’ın Tarihsel Gelişimi

‘Boğaziçi Yerleşmelerinden Emirgan Bölgesi’nin Tarihsel Gelişimi’ başlıklı çalışma dört bölümden oluşmaktadır. Birinci bölümde çalışmanın giriş kısmında çalışmanın amacı, çalışmanın kapsamı ve çalışmanın yöntemi açıklanmıştır. Amaç; Boğaziçi yerleşmelerinden biri olan Emirgan Bölgesi’ni tarihsel perspektif içinde ele alarak gelişimini ortaya koymak ve son dönem değişimlerini belirleyerek bir değerlendirme yapmaktır. İkinci bölümde; öncelikle Emirgan’ın konumu, sınırları, topografya, iklim ve bitki örtüsü gibi fiziksel özelliklerinin bilgileri verilmiştir. Fiziksel verilerin ardından bölgenin nüfus, ulaşım, sosyal yaşam gibi sosyokültürel özellikleri incelenerek tez çalışmasına eklenmiştir. Bu özelliklerin açıklanmasının ardından Emirgan Bölgesi’nin tarihsel gelişimi Bizans, Osmanlı ve Cumhuriyet olmak üzere üç dönem halinde incelenmiştir. Bizans döneminde bölgenin durumu ile ilgili araştırmalar ele alınmış, bölgede ilk yerleşmenin başladığı Osmanlı dönemi üzerinde durulmuştur. Cumhuriyet döneminde ise bölgenin tarihsel gelişimine etki eden unsurlar ele alınmıştır. Üçüncü bölümde; ikinci bölümde incelenen tarihsel dönemlerin bilgisi ışığında Emirgan yerleşmesinde tarihsel dönemler içinde gelişen mimari yapılanma çalışılmıştır. Osmanlı döneminde bölgede oluşmaya başlayan ve giderek gelişen köy içi yerleşmesinin kentsel elemanları ve mimari yapının bütününü oluşturan önemli yapı birimleri incelenmiştir. Bu yapılardan Emirgan Bölgesi’ndeki günümüze ulaşan en önemli kıyı yapısı olan Şerifler Yalısı üzerinde durulmuştur. Osmanlı döneminin ardından tarihi silsile içerisindeki bir sonraki dönem olan Cumhuriyet döneminde Emirgan’da meydana gelen mimari gelişimler iki kısımda incelenmiştir. İlk kısımda; 1923 tarihinde Cumhuriyetin ilanından tüm Boğaziçi yerleşmelerinde kentsel dokuyu ve mimari yapılanmayı etkileyen Boğaziçi Kanunu’nun yürürlüğe girdiği 1983 tarihine kadar olan zaman dilimini kapsayan dönemde Emirgan’daki mimari yapılanma incelenmiştir. İkinci kısımda ise 1983 yılında Boğaziçi Kanunu’nun yayınlanmasının ardından günümüze kadar olan süreçte oluşan yeni konjonktüre bağlı gelişen mimari yapılanma incelenmiştir. Farklılaşma sürecini etkileyen unsurlar olan yasa değişiklikleri, koruma kanunları ve bölgede süregelen kentsel elemanlarda ve mimari yapılarda gerçekleşen yenileme çalışmaları araştırılarak Emirgan’a olan etkisi bu bölümde ele alınmıştır. Son bölüm olan sonuç kısmında ise tez kapsamında ele alınan konulara kısaca değinilerek Emirgan Bölgesi ve mimari yapılanması hakkında genel bir değerlendirmenin ardından bölgenin sağlıklı gelişimi için önerilerde bulunulmuştur.The project "The Historical Development of Emirgan Region of Bosphorus" consists of four parts. In the first part; purpose, scope and method of the project is disclosed. The purpose is to evaluate the development of Emirgan, a Bosphorus settlement, from a historical perspective regarding the recent changes. From the general Bosphorus subject, the thesis focuses on the Emirgan region in the second and third parts. In the second part, the physical characteristics such as the location, boundaries, topography, climate and vegetation are given along with the socio-cultural details like population, transportation and social life. Following the explanation of these properties, the historical development of the region is studied through three eras: The Byzantine, Ottoman and Republican periods. In the part about the Byzantine era, studies regarding the region’s situation were examined, beginning of the settlements in the Ottoman period were accentuated, and for the Republican period the factors effecting the region were analysed. In the third part, the evolving architectural structure of Emirgan is studied in the light of the historical details examined in the second part. The urban elements of the village settlements which started to flourish in the Ottoman period, and the important architectural elements forming the complete settlements are examined. The work focuses on Şerifler Yalisi, the most important coastal structure of the Emirgan region that has survived to this day. Following the Ottoman era, the sequence continues with the Republican period and the architectural developments of that period were examined in two parts. The first part begins with the establishment of the Republic and covers the architectural developments in Emirgan until 1983, the year when the Bosphorus Act came became operative and affected the urban structure and architectural structuring in all Bosphorus settlements. And in the second part, the era after the Bosphorus Act of 1983 was covered up until today, and the architectural structuring resulting from the new conjuncture. The effect of changing laws and social life on the Bosphorus' architectural structure is evaluated considering the Ottoman period and earlier Republican period, along with the last 30 years of the Republican period. And in the last part, a general evaluation and recommendations have been shared regarding the topics discussed in the thesis

Inferring hidden features in the Internet (PhD thesis)

The Internet is a large-scale decentralized system that is composed of thousands of independent networks. In this system, there are two main components, interdomain routing and traffic, that are vital inputs for many tasks such as traffic engineering, security, and business intelligence. However, due to the decentralized structure of the Internet, global knowledge of both interdomain routing and traffic is hard to come by. In this dissertation, we address a set of statistical inference problems with the goal of extending the knowledge of the interdomain-level Internet. In the first part of this dissertation we investigate the relationship between the interdomain topology and an individual network’s inference ability. We first frame the questions through abstract analysis of idealized topologies, and then use actual routing measurements and topologies to study the ability of real networks to infer traffic flows. In the second part, we study the ability of networks to identify which paths flow through their network. We first discuss that answering this question is surprisingly hard due to the design of interdomain routing systems where each network can learn only a limited set of routes. Therefore, network operators have to rely on observed traffic. However, observed traffic can only identify that a particular route passes through its network but not that a route does not pass through its network. In order to solve the routing inference problem, we propose a nonparametric inference technique that works quite accurately. The key idea behind our technique is measuring the distances between destinations. In order to accomplish that, we define a metric called Routing State Distance (RSD) to measure distances in terms of routing similarity. Finally, in the third part, we study our new metric, RSD in detail. Using RSD we address an important and difficult problem of characterizing the set of paths between networks. The collection of the paths across networks is a great source to understand important phenomena in the Internet as path selections are driven by the economic and performance considerations of the networks. We show that RSD has a number of appealing properties that can discover these hidden phenomena