Baris Yamansavascilar

Research Scientist

About Me

Hi, welcome to my personal website! After I have got my MS degree in July 2019 from Bogazici University Computer Engineering Department, currently I am continuing my studies as a PhD student in the same department under the guidance of Prof. Cem Ersoy. My objectives are to be up to date and to perform great research & applications by following the latest innovations. In this website, you can find information about me as either personal or professional.

OFDMA Scheduler Development for IEEE 802.11ax Dual Band Wireless Access Point with MU-MAC Frame Support

March 2019 – March 2020

This project aimed at implementing an MU MAC OFDMA scheduler on an AP that supports IEEE 802.11ax standard (Wifi 6). The expectation from the scheduler was to consider the fairness and efficiency between HE STAs regarding their uplink and downlink traffic. The project was funded by AirTies Wireless Networks.

Service Management on Multitier IT Architecture

January 2017 – January 2019

The goal of this project was to bring cloudlets providing service with minimal latency, and cloud servers, which can service when there is a need for high processing power while latency is not so significant, together in a multi-tier architecture. This project was funded by Bogazici University Scientific Research Projects (BAP).

Distributed Data Processing and Applications for Mobile Edge Computing

August 2017 – June 2018

Considering the tremendous amount of data emerging by mobile devices each day, Mobile Edge Computing (MEC) solutions would have critical importance. To this end, this research project aimed at finding possible effective solutions. This project was funded by Netas.

Making Art More Accessible

03 April 2017 – 21 July 2017

Although there are specialized platforms for nearly all popular forms of content (e.g. Flickr for photos, IMDB for movies etc.), a platform dedicated to art (and particularly to painting and illustration) has yet to emerge in an Art Merchandise Market estimated to be worth 25 Billion USD worldwide. There have been some attempts towards that objective but they did not fully include the public. Thus, the goal of initiatives such as USEUM (an online encyclopedia of art) is to make art more accessible to the public, challenging the stereotype of art being distant and exclusive. This project was assigned and funded by the Colibri-Erasmus+ programme that includes only graduate students from 8 European countries.

Fault Tolerant Data Plane Using SDN

3 October 2016 – 16 December 2016

Software-defined Networks (SDN) increase their importance considering Internet technology. However, because of their centralized nature, they are vulnerable in terms of reliability and fault-tolerance issues both on data and control planes. In this study, these issues were investigated by considering various network and performance measurements, and fault tolerance on data plane was focused. In the experiments, the impact of the topology size, frequency of packets, and the number of flows in the current route on the recovery time were tested.

Advanced Threat Detection Using Machine Learning Techniques

July 2015 – July 2016

The project aimed at detecting and preventing Intrusion and Advanced Persistent Thread (APT) attacks via manifesting anomalies in network flows and system logs using machine learning algorithms. DeterLab Testbed was used as a development and test platform for the various work packages of the project. Moreover, it was funded by The Scientific and Technological Research Council of Turkey (TUBITAK).

Undergrad

Network Traffic Classification Using Machine Learning Techniques

September 2014 – June 2015, Senior Project (Thesis)

Recent developments on the Internet have led to increase the importance of network traffic classification. Classification of large-scale network traffic can provide much important information for network management, QoS and network security. In this study, the influence of different network speeds to accuracy was evaluated and a comparison between packet-based and time-based approaches was performed.

Introduction (in Turkish)

Activity Recognition on Smartphones

September 2013 – June 2014, Junior Project

Great hardware and software capabilities of mobile devices allow us to research new scientific fields. Activity recognition is one of the main research areas for smartphones. Built-in sensors of a standard smartphone, such as accelerometer, magnetometer, gyroscope, enable us to predict the daily activities of a person. However, continuous samplings from each sensor increase the CPU utilization and cause the battery to die sooner. In this study, we focused on the window sizes and the sampling rates in order to observe how they affect to the accuracy and CPU utilization.

Research Interests

  • 5G, Edge Computing

  • Deep Learning, Machine Learning

  • SDN, NFV, Mobile Networks

Education

PhD Student, Computer Engineering

Bogazici University

27.08.2019 – Present

MSc, Computer Engineering

Bogazici University

25.08.2016 – 04.07.2019

MS Thesis: Fault Tolerance in The Data Plane of Software-Defined Networks

BS, Computer Engineering

Yıldız Technical University

02.09.2010 – 03.07.2015

Senior Project (Thesis): Network Traffic Classification Using Machine Learning Techniques
Junior Project: Activity Recognition on Smartphones

Work Experience

Bogazici University Computer Networks Research Laboratory (NetLab)

Research Assistant

09.2016 – Present

I have been research assistant in NetLab since my admission to Bogazici University in 2016. I worked on several projects under the supervision of Prof. Cem Ersoy. My experience in NetLab has formed my abilities in research and provided me invaluable experience.

Yıldız Technical University Intelligent Systems Lab

Researcher

22.06.2015 – 01.07.2016

I was affiliated with the project namely "Advanced Threat Detection Using Machine Learning Techniques" for one year in Intelligent Systems Lab at YTU. This project was funded by TUBITAK and provided me important insight into the relationship between academia and industry. Moreover, it enhanced my research experience.

Microsoft

Intern

04.08.2014 – 29.08.2014

I attended the Microsoft Summer School as an intern for a month. During the internship, Microsoft demonstrated its latest technologies and developments. Moreover, leading people in technology and business were invited to present their experiences and gave advice in sessions.

Ziraat Technology

Intern

30.06.2014 – 25.07.2014

During the internship, I worked in the Network Communication & Security Department. Firstly, basic terms for the network such as IP, IP Addresses, NAT, Proxy, and Firewall were investigated. Then, based on these terms, how network security is built and managed in a company was observed. Moreover, attack and defense mechanisms for computer networks were examined.

Turk Telekom

Intern

01.07.2013 – 28.08.2013

In Turk Telekom, I worked in the Enterprise Resource Application Department. I learned Enterprise Resource Planning (ERP) concept and then gained skills in SAP. In addition, I studied ABAP, which is the programming language of the SAP.

Publications

B. Yamansavascilar, A.C. Baktir, A. Ozgovde, C. Ersoy, "Fault Tolerance in SDN Data Plane Considering Network and Application Based Metrics", arXiv preprint arXiv:1912.11849, 2020.

B. Yamansavascilar, A.C. Baktir, A. Ozgovde, C. Ersoy, "Enhancing QoE for Video Streaming Considering Congestion: A Fault Tolerance Approach", IEEE INFOCOM Workshops, pp. 258-263, 2019, Paris, France.

B. Yamansavascilar, A. C. Baktir, A. Ozgovde, and C. Ersoy, “Fault Tolerant Data Plane Using SDN”, The 25th Signal Processing and Communications Applications Conference (SIU), 2017, Antalya, Turkey.

B. Yamansavascilar, M. A. Guvensan, A. G. Yavuz, and M. E. Karsligil, “Application Identification via Network Traffic Classification”, The International Conference on Computing, Networking and Communications (ICNC), pp. 843-848, 2017, San Francisco, USA.

B. Yamansavascilar, M. A. Guvensan, “Activity Recognition on Smartphones: Efficient Sampling Rates and Window Sizes”, The International Workshop on the Impact of Human Mobility in Pervasive Systems and Applications (PerMoby), pp. 1-6, 2016, Sydney, Australia.

Welcome to my blog!

In this page, I will share my thoughts about several topics including people, cinema, history, recommendation, life experience etc. My intention to build this blog is that I want to share my feelings independently due to social media platforms generally either do not provide such a place or (even if they do) do not meet the same effect. Moreover, having a blog is cool :) . Even though the content of my website is written in English, I would write some of my blog articles in Turkish since I believe that I can express my feelings much better in this way for particular topics.

28-05-2018

Color in Photography: Autochrome Lumiere

The most beautiful thing with the photography is that it confines the particular moment forever. Since it achieves the one of the earliest desire of human being that preserving memories (especially young reflectance of themselves), it immediately gained attention and became popular. The mechanism is actually so basic and known from the earlier centuries. If you have a simple box that contain a single slight hole, in order to obtain light from a particular direction, you can get a reverse image of the original one standing in front of the hole. This is called as camera obscura. The photography is actually based on this concept. However, since this article is not about basics of the photography, I do not intend to give more details. The topic is about a method for early color photography.

When photography was invented, it was so popular as expected but there was a problem: people live in a color world, not black&white as in photos. To solve this issue, people started to work and suggested some solutions for color photography. There were some efforts to meet the desired result but most of them were cumbersome considering their method. There were not practical. For example, one of them required to take three different photos from same position using three different filters consisting colors including red, green, and blue in order to obtain the real color of the objects/people/moment. On the other hand, Lumiere brothers, who had invented the cinematograph, which is actually the cinema, developed more efficient method using potato starches: Autochrome Lumiere. This technique consisted of a glass plate including infinitesimal particles, which are randomly separated potato starches with the mean length of 15 microns, dyed with red-orange, green, and blue-violet colors. As you can imagine, this plate was transparent and the light was passed through it producing the color of the particular moment. The results were quite good and because of the technique, they were causing some kind of pointillist effect. Moreover, some examples were like oil painting. Due to its success, Autochrome Lumiere were considered as the main method for the color photography by people, especially artists. You can see some examples below.




Looking a color photo taken at least 20-30 years ago always impress me. The reason is that I can see that there was a life in that time and those people were young like me. Afterwards, seeing people getting older also has an impact on me. On the other hand, if the photo is black&white, its effect is lesser on me since black&white photos remind the old times physiologically. Since I am used to see color photos (not colorized!) from 1960s at most, realizing the fact that there was a creative method to take original color photos in 1910s literally shocked me! Especially, if you examine three photos below, you may understand what I have felt.


These photos were taken in 1913(!) by electrical engineer Mervyn O'Gorman at Lulworth Cove in Dorset, England. She was, namely Christine, his daughter. When I first saw this, I thought that it is an advertisement and taken nowadays. Since we are used to see black&white photos considering that era, we generally missed that there is no difference between ours and those people regarding general thoughts, following fashion etc. However, seeing a color photo can change this misperception easily.

After the invention of Autochrome Lumiere, photographers, who had the opportunity to reach and buy those glass plates, took photos from all over the world. You can find some of them online, especially in photo apps like Pinterest, Flickr etc. I explored some of those photos with a great excitement. As one can imagine, each of them express the era including enthusiasm of 20th century French romanticism which continued to late 1940s. On the other hand, apart from the photographers, the color in the photographs took attention from collectors. One of them, Albert Kahn, a French banker, created the most important archive of Autochrome Lumiere: The Archives of Planet. It includes 72.000 color photographs from 50 countries! Subsequently, I wondered that if there are color photos from my country, Turkey. What I found was beyond my imagination.

Albert Kahn entrusted many photographers to take color photos from various countries in order to create his project The Archives of Planet. Some of those photographers including Stéphane Passet, Auguste Léon, and Frederic Gardner, came to Turkey and took very important photographs from İstanbul, İzmir, Ankara, Karahisar, Turgutlu, Afyon, and Antakya between 1912 – 1929. Since I used to see photos of Istanbul as black&white, color photographs of the city impress me. You can see some them below.




As you know, Turkey was continuously at war from 1912 to 1922, therefore the photographs taken in Anatolia are so important since they show the damage and poverty in color. If you investigate those photos from the website of Archives of Planet, you can see that even faces of people tell you their sad stories. However, even though all photos taken in Turkey are valuable for me, the following is the most valuable: The photo below is the only original color photograph of Mustafa Kemal Atatürk (there are few others taken in same day with Rauf Orbay but I don’t include them here), who led the Turkish Independent War and founded Republic of Turkey. The photo is taken by Frederic Gardner in 29 December 1922 using Autochrome technique while he was employed in Anatolia. In those days, Greeks had been defeated by Mustafa Kemal Pasha but the republic was not declared yet.


There are two additional photos below that I want to mention and express my feelings about. First one was taken at the chamber of council of ministers at Grand National Assembly in Ankara, 1922. For me, it is so ironic and amazing to see the well-known black&white photograph of Mustafa Kemal Atatürk, which is placed on the wall at top right, in a color photo taken in 1922! Another photograph is taken at the general assembly hall of Grand National Assemby. Since I saw the various black&white versions of this photo, I am surprised to realize that the desks were blue! By the way, note that, the republic was declared in this very small hall…



In color photography, Autochrome Lumiere was the pioneer until 1930s in which the color film, Kodachrome, invented by Kodak. Even though taken photographs using Autochrome technique were so beautiful and unique, images were not as exactly true as the photos produced by color film. Moreover, glass plates were so fragile. Thus, it was superseded by Kodachrome. Even though Lumiere company introduced color film versions of Autochrome such as Lumiere Filmcolor sheet film in 1931, Lumicolor roll film in 1933, and lastly Alticolor in 1952, they were not successful and discontinued.

The most interesting thing about color photography is that it was not widespread until late 1960s even though it was invented in early 1910s and matured in 1930s. Apart from common people, leaders of that era also preferred black&white photographs. There were two reasons for this. First, taking color images were expensive comparing to the traditional black&white photographs. However, all we know that if people really like something, they would go, buy and use it. For example, I remember that Steve Ballmer, former CEO of Microsoft, said that no one would buy iPhone because it is so expensive. However, even though the original iPhone was so expensive when it was first put on the market, people bought it with an enthusiasm. I think this is same for all new products and technologies so it was not the main reason that people did not choose color images. Therefore, the real (second) reason was that people did not like the idea, which is color photo. It sounds like a joke but this was the reality in that time. People thought black&white photos are so dramatic & artistic, and color images did not reflect them. They thought that they already see each other in a color, so images should be different. This is actually true; if you compare same photos with color and without color you can clearly see that black&white is more cool. This opinion lasted very long time and thus people preferred black&white photos.

It is so peculiar that in that times taking a photograph was a ritual and significant for all families and people, while today we can use it as a basic function of our phones which are in our pocket. Things are changing over time, so maybe some objects we use today would be a basic toy for people that live in the future. However, one thing will remain same: people always want to show themselves and thus, they find a way/tool to perform this. The day before there was portrait, yesterday there was photograph, and today there is social media.

Bogazici University
Department of Computer Engineering
Office: BM 46 (NetLab)
34342 Bebek, Istanbul, Turkey
Email: baris.yamansavascilar@boun.edu.tr