Sürdürülebilir Yeşil Kampüs Koleksiyonu / Sustainable Green Campus Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7755

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Access Monitoring System for Distributed Firewall Policies
(Izmir Institute of Technology, 2008) Çakı, Oğuzhan; Tuğlular, Tuğkan; 03.04. Department of Computer Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Internet has provided several benefits in terms of information sharing. However, Internet is an insecure environment that can cause threats to private networks. As a result, network security becomes a critical issue. One of the important tools used in network security is firewall. Firewalls protect a private network from external threats by restricting network traffic according to predefined security rules. Basically, firewalls apply these rules to each packet that passes over them. Distributed firewalls are a new approach to firewall to overcome some drawbacks of traditional firewalls. Distributed firewall design is based on the idea of enforcing the policy rules at the endpoints rather than a single entry point to network. Management of policy rules is a critical issue in both traditional and distributed firewalls. We propose a monitoring application for distributed firewall policies to keep track of actions (create, read. update, delete) performed on policy rule set. The resulting data produced by the monitoring application will be very helpful in policy management process.
Citation - WoS: 4
Citation - Scopus: 8
Advances in Model-Based Testing of Graphical User Interfaces
(Academic Press Inc., 2017) Belli, Fevzi; Beyazıt, Mutlu; Budnik, Christof J.; Tuğlular, Tuğkan; 03.04. Department of Computer Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Graphical user interfaces (GUIs) enable comfortable interactions of the computer-based systems with their environment. Large systems usually require complex GUIs, which are commonly fault prone and thus are to be carefully designed, implemented, and tested. As a thorough testing is not feasible, techniques are favored to test relevant features of the system under test that will be specifically modeled. This chapter summarizes, reviews, and exemplifies conventional and novel techniques for model-based GUI testing.
An Analysis of Key Generation Efficiency of Rsa Cryptosystem in Distributed Environments
(Izmir Institute of Technology, 2005) Çağrıcı, Gökhan; Koltuksuz, Ahmet Hasan; 03.04. Department of Computer Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
As the size of the communication through networks and especially through Internet grew, there became a huge need for securing these connections. The symmetric and asymmetric cryptosystems formed a good complementary approach for providing this security. While the asymmetric cryptosystems were a perfect solution for the distribution of the keys used by the communicating parties, they were very slow for the actual encryption and decryption of the data flowing between them. Therefore, the symmetric cryptosystems perfectly filled this space and were used for the encryption and decryption process once the session keys had been exchanged securely. Parallelism is a hot research topic area in many different fields and being used to deal with problems whose solutions take a considerable amount of time. Cryptography is no exception and, computer scientists have discovered that parallelism could certainly be used for making the algorithms for asymmetric cryptosystems go faster and the experimental results have shown a good promise so far. This thesis is based on the parallelization of a famous public-key algorithm, namely RSA.
Citation - Scopus: 4
An Aspect-Lexicon Creation and Evaluation Tool for Sentiment Analysis Researchers
(Springer Verlag, 2012) Husaini, Mus'ab; Koçyiğit, Ahmet; Tapucu, Dilek; Yanıkoğlu, Berrin; Saygın, Yücel; 03.04. Department of Computer Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
In this demo paper, we present SARE, a modular and extendable semi-automatic system that 1) assists researchers in building gold-standard lexicons and evaluating their lexicon extraction algorithms; and 2) provides a general and extendable sentiment analysis environment to help researchers analyze the behavior and errors of a core sentiment analysis engine using a particular lexicon.
Business Activity Monitoring for Logistics Management Systems
(Izmir Institute of Technology, 2013-07) Titiz, Dilek; Ayav, Tolga; 03.04. Department of Computer Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Enterprises use different software for different purposes, such as accounting management, customer relationships, so that information technologies become an integral part of business processes. A business process turns out to be a combination of these different software, besides the received information/data by one of software tools that comes from another one. Different software systems cannot have been aware of each other directly. When the domain under consideration is container logistics, in addition to the different software, there are many relationships with other companies and so there are many different systems, variable types and file types that are being used. There are different transportation modes like highway, marine or airway, and by the expansion of intermodal transportation, tracking data is getting harder. For container logistics being a complicated business, tracking data is a necessity. The necessity is to track and to control the data that comes from outer systems and inner systems to an interoperable platform. This necessity enables trackable business processes and thus increases the business performance. In the scope of this thesis, a business activity monitoring environment is created in case of ARKAS Holding, which works on container logistics domain and Bimar Inc., which is the software provider of it. As it was mentioned above, this tracking needs cause to creation of the proposed and implemented monitoring environment for such a case of ARKAS Holding that does intermodal transportation, which has many endpoints in its business processes and there are too many data to be tracked. There are many different endpoints, such as marine, roadway and depot, in container logistics; also there are many different data types that are coming from different systems. Thus, the â€˜Business Activity Monitoringâ€™ environment is created as this thesisâ€™ subject to make these different systems talk to each other, also to enable gathering data directly and automatically to achieve real-time monitoring.
A Cluster Based Communication Architecture for Distributed Applications in Mobile Ad Hoc Networks
(Izmir Institute of Technology, 2006) Dağdeviren, Orhan; Erciyes, Kayhan; 03.04. Department of Computer Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
In this thesis, we aim to design and implement three protocols on a hierarchical architecture to solve the balanced clustering, backbone formation and distributed mutual exclusion problems for mobile ad hoc network(MANET)s. Our ¯rst goal is to cluster the MANET into balanced partitions. Clustering is a widely used approach to ease implemen-tation of various problems such as routing and resource management in MANETs. We propose the Merging Clustering Algorithm(MCA) for clustering in MANETs that merges clusters to form higher level of clusters by increasing their levels. Secondly, we aim to con-struct a directed ring topology across clusterheads which were selected by MCA. Lastly, we implement the distributed mutual exclusion algorithm based on Ricart-Agrawala algo-rithm for MANETs(Mobile RA). Each cluster is represented by a coordinator node on the ring which implements distributed mutual exclusion algorithm on behalf of any member in the cluster it represents. We show the operations of the algorithms, analyze their time and message complexities and provide results in the simulation environment of ns2.
Citation - Scopus: 2
A Comparative Study of Modularity-Based Community Detection Methods for Online Social Networks
(CEUR Workshop Proceedings, 2018) Karataş, Arzum; Şahin, Serap; 03.04. Department of Computer Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Digital data represent our daily activities and tendencies. One of its main source is Online Social Networks (OSN) such as Facebook, YouTube etc. OSN are generating continuously high volume of data and define a dynamic virtual environment. This environment is mostly represented by graphs. Analysis of OSN data (i.e.,extracting any kind of relations and tendencies) defines valuable information for economic, socio-cultural and politic decisions. Community detection is important to analyze and understand underlying structure and tendencies of OSNs. When this information can be analysed successfully, software engineering tools and decision support systems can produce more successful results for end users. In this study, we present a survey of selected outstanding modularity-based static community detection algorithms and do comparative analysis among them in terms of modularity, running time and accuracy. We use different real-world OSN test beds selected from SNAP dataset collection such as Facebook Ego network, Facebook Pages network (Facebook gemsec), LiveJournal, Orkut and YouTube networks.
A Dedicated Server Design for Physical Web Applications
(Izmir Institute of Technology, 2019-07) Abdennebi, Anes; Ayav, Tolga; 03.04. Department of Computer Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
With the huge impressive technological improvements the world is witnessing where giants like Facebook, Google, Apple, Microsoft and other technology companies are offering different services to millions of clients, services which don’t take usually more than seconds to be within the users’ devices besides the Physical Web applications that makes things interacts, having entities and can be reached based on the proximity context without omitting the incoming IoT infrastructure that would make 20.4 billion devices connected by 2020, the amount of data transferred, and services provided will be enormous and along with that, the big energy consumer standing behind providing clients with the needed data and services instantly, the web servers. Although it has a magnificent performance and responds to billions of queries and requests, however, there is still a crucial point which must be highlighted, the remarkable amounts of energy consumption by these servers. Therefore, this work is proposing a new approach in order to reduce the energy consumption in such a scenario where the 18-core energy efficient computer Parallella board will be used in order to create an energy efficient server that can offer many services triggered by various devices or any ordinary web requests across any environment and to prove also that using a cluster of Parallella supercomputers may perform as other similar servers dealing with web content (e.g. Raspberry Pi server). We will show how would these boards work under low energy feeding where users can access a web content hosted on a Parallella cluster. The source codes of the project are available on GitHub.
Designing Programmable Logic Controller for Data Acquisition and Control
(Izmir Institute of Technology, 2010) Gözütok, Mehmet Emre; Ayav, Tolga; 03.04. Department of Computer Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
in this study, a new dsPIC microcontroller based PLC design for requirements of data acquisition, signal processing and control applications has been discussed. The aim of the study was to realize of today's automation applications with a more economic, convenient, and functional device other than PLC applications. This device is a general purpose product available in ali areas. it is used to determine the city power grid harmonics. The circuit schema of the device is drawn in Multisim environment. The design of the printed circuit board is implemented in Ultiboard. The Microchip IDE is used for writing the codes and programming the MCU. The C30 compiler is used for compiling the codes which is distributed free of charge by Microchip. To evaluate the performance of the product, the harmonics in the electricity netvvork are tested. The operating time of the two main functions which are used in the FFT algorithm that was used for determining those harmonics were observed and results were expressed visually. Further development that could be done, by other researchers, in the future, is also discussed in the final chapter.
A Detection and Correction Approach for Overflow Vulnerabilities in Graphical User Interfaces
(Izmir Institute of Technology, 2009) Müftüoğlu, Can Arda; Tuğlular, Tuğkan; 03.04. Department of Computer Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
The objective of this thesis is to propose an approach for detecting overflow vulnerabilities such as buffer and boundary overflows by using static analysis and correcting these vulnerabilities by applying a correction mechanism which uses static code insertion. GUI is tested by specifying user interface requirements and converting this specification into an event-sequence model. Decision table notion is used for modeling the dependencies and boundary restrictions on input data and generating test cases. The test cases are applied to the GUI as inputs manually in real environment. The faults are observed. Then, the overflow vulnerability analysis tool is used to analyze the source code of the program. The deficiencies related to overflow vulnerabilities are found by static analysis. After that, the correction mechanism is applied to the deficient parts of the source code. The software is tested in real environment again. The proposed approach is observed to be successful for detecting and correcting overflow vulnerabilities in GUIs.
Developing Applications On-Board of Robots With Becerik
(Trans Tech Publications, 2012) Kumova, Bora İsmail; Takan, Savaş; 03.04. Department of Computer Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Robot applications are mostly first developed on a computer and thereafter loaded onto the robot. However, in many situations, developing applications directly on the robot may be more effective. For instance, children who have not learned using a computer yet and who develop their robot applications while playing. Or for instance in the robots' operating environment, where there is no computer available. In this contribution we present the properties of the software tool becerik, for developing applications on-board a robot and for running them in multi-tasking mode concurrently. Furthermore, we introduce the programming language of the applications that has the same name becerik, which consists of only 6 commands. © (2012) Trans Tech Publications, Switzerland.
Development of a Distributed Firewall Administration Tool
(Izmir Institute of Technology, 2008) Erdoğan, Yunus; Tuğlular, Tuğkan; 03.04. Department of Computer Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Today firewalls not only guard internal computer networks but also individual personal computers against malicious and unauthorized accesses from outside. The purpose of this study is to create architecture and its corresponding application to manage distributed firewalls running on Microsoft Windows platform. Distributed Firewall Administration is about creating a management center for a network composed of the firewalls running on Microsoft Windows platform. Main important part of this work is to determine distributed firewall network topology with breadth-first search and depth-first search algorithms.The Microsoft Windows Firewall API makes it possible to programmatically manage the features of firewalls running on windows platform by allowing applications to create, enable and disable firewall exceptions. This study used the Windows Firewall API to manage the features of it. This API is only reachable using C/C++ low level programming languages.Distributed Firewall Administration Tool (DFAT) can add, modify or delete rules on the end-user firewall rule set, these rules stored on the database. This tool works on a distributed environment, there is a parent child relationship between firewalls. Parent firewalls have right to manage its child firewall.s rule set. Firewalls introduce themselves to each other with broadcast method.
Distinct Encoded Records Join Operator for Distributed Query Processing
(Izmir Institute of Technology, 2012) Öztürk, Ahmet Cumhur; Ergenç, Belgin; 03.04. Department of Computer Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Nowadays distributing data among different locations is very popular due to needs of business environment. In today's business environment, accessible, reliable, and scalable data is a critical need and distributed database system provides those advantages. It is a need to transfer data between sites while processing query in distributed database system, if the connection speed between sites is low then transmitting data is very time consuming. Optimizing distributed query processing is different from optimizing query processing in local database system. Most of the algorithms generated for distributed query processing focus on reducing the amount of data transferred between sites. Join operation in database system is for combining different tables with a common join attribute value, if the tables that are put in a join operation are at different locations then some of the tables are needed to be transferred to between sites. Join operation optimization algorithms in distributed database system focus on reducing the amount of data transfer by eliminating redundant tuples from relation before transmitting it to the other site. This thesis introduces a new distributed query processing technique named distinct encoded records join operation (DERjoin) which considers duplicated join attributes in a relation and eliminates them before sending the relation to another site.
Citation - WoS: 8
Citation - Scopus: 13
A Distributed Backbone Formation Algorithm for Mobile Ad Hoc Networks
(Springer Verlag, 2006) Dağdeviren, Orhan; Erciyeş, Kayhan; 03.04. Department of Computer Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Construction of a backbone architecture is an important issue in mobile ad hoc networks(MANET)s to ease routing and resource management. We propose a new fully distributed algorithm for backbone formation in MANETs that constructs a directed ring architecture. We show the operation of the algorithm, analyze its message complexity and provide results in the simulation environment of ns2. Our results conform that the algorithm is scalable in terms of its running time and roundtrip delay against mobility, surface area, number of nodes and number of clusterheads.
A Distributed Multiprecision Cryptographic Library Design
(Izmir Institute of Technology, 2005) Hışıl, Hüseyin; Koltuksuz, Ahmet Hasan; 03.04. Department of Computer Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Cryptographic schemes require specialized software libraries to work with large numbers on fixed-precision processors. The concept is known as multiple-precision computation. In this thesis, we aim to review the multiple-precision algorithms with the contemporary modifications. With this motivation, we develop a new multiprecision library named CRYMPIX and we carefully benchmark CRYMPIX in comparison with the fastest alternatives. We also develop a distributed wrapper for computationally expensive functions. Hence, we provide an abstraction method for the higher level cryptographic implementations by allowing them run in a distributed environment without containing any specialized code for distribution.
A Dominating Set Based Communication Architecture for Distributed Applications in Mobile Ad Hoc Networks
(Izmir Institute of Technology, 2007) Çokuslu, Deniz; Aytaç, İsmail Sıtkı; 03.04. Department of Computer Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
In this thesis, we aim to design and implement algorithms in a distributed environment in order to solve clustering, backbone formation and efficient routing problems for mobile ad hoc networks(MANET)s. Our first goal is to find a connected dominating set (CDS), then construct clusters using the clusterhead information and extend this approach to multi-level clusters. We propose a new Connected Dominating Set based clustering algorithm for clustering in MANETs. Our algorithm is based on Wu and Li's algorithm, however we provide significant modifications and heuristics such as considering the degrees of the nodes during marking process. We also extend our algorithm in order to generate a hierarchy of clusters. Our second goal is to implement a flooding based routing mechanism on top of CDS based clusters. We propose a two level flooding mechanism by using the CDS members as the gateways of the clusters. We describe the algorithms, analyze their time and message complexities and measure their performance in the simulation environments.
Dynamic Itemset Hiding Under Multiple Support Thresholds
(Izmir Institute of Technology, 2018-07) Öztürk, Ahmet Cumhur; Ergenç Bostanoğlu, Belgin; 03.04. Department of Computer Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Data sharing is commonly performed between organizations for mutual benefits. However, if confidential knowledge is not hidden before the data is published it may pose threat to security and privacy. The privacy preserving frequent itemset mining is the process of hiding sensitive itemsets from being discovered with any frequent itemset mining algorithm. The privacy constraint of sensitive itemset hiding is sensitive threshold. If support of a given sensitive itemset is under the sensitive threshold, then this sensitive itemset is considered as non-interesting and hidden. One possible way of decreasing support of sensitive itemsets under predefined sensitive threshold is deleting items from a set of transaction. This type of frequent itemset sanitization is called distortion based frequent itemset hiding. The main focus of this thesis is to preserve sensitive itemsets with considering the multiple sensitive thresholds on both static and dynamic environments. Three different distortion based frequent itemset hiding algorithms proposed; Pseodo Graph Based Sanitization (PGBS), Itemset Oriented Pseudo Graph Based Sanitization (IPGBS) and DynamicPGBS are proposed. Both PGBS and IPGBS algorithms are designed for static environment and the DynamicPGBS algorithm is designed for the dynamic environment. The main objective of these three algorithms is to hide all sensitive itemsets with giving minimum distortion on non-sensitive knowledge and data in the resulting sanitized database.
Citation - WoS: 22
Citation - Scopus: 29
Dynamic Replication Strategies in Data Grid Systems: A Survey
(Springer Verlag, 2015-11) Tos, Uras; Mokadem, Riad; Hameurlain, Abdelkader; Ayav, Tolga; Bora, Şebnem; 03.04. Department of Computer Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
In data grid systems, data replication aims to increase availability, fault tolerance, load balancing and scalability while reducing bandwidth consumption, and job execution time. Several classification schemes for data replication were proposed in the literature, (i) static vs. dynamic, (ii) centralized vs. decentralized, (iii) push vs. pull, and (iv) objective function based. Dynamic data replication is a form of data replication that is performed with respect to the changing conditions of the grid environment. In this paper, we present a survey of recent dynamic data replication strategies. We study and classify these strategies by taking the target data grid architecture as the sole classifier. We discuss the key points of the studied strategies and provide feature comparison of them according to important metrics. Furthermore, the impact of data grid architecture on dynamic replication performance is investigated in a simulation study. Finally, some important issues and open research problems in the area are pointed out.
End-To Security for Mobile Devices
(Izmir Institute of Technology, 2004) Kayayurt, Barış; Tuğlular, Tuğkan; Tuğlular, Tuğkan; 03.04. Department of Computer Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
End-to-end security has been an emerging need for mobile devices with the widespread use of personal digital assistants and mobile phones. Transport Layer Security Protocol (TLS) is an end-to-end security protocol that is commonly used in Internet, together with its predecessor, SSL protocol. By using TLS protocol in mobile world, the advantage of the proven security model of this protocol can be taken.J2ME (Java 2 Micro Edition) has been the de facto application platform used in mobile devices. This thesis aims to provide an end-to-end security protocol implementation based on TLS 1.0 specification and that can run on J2ME MIDP (Mobile Information Device Profile) environment. Because of the resource intensive public-key operations used in TLS, this protocol needs high resources and has low performance. Another motivation for the thesis is to adapt the protocol for mobile environment and to show that it is possible to use the protocol implementation in both client and server modes. An alternative serialization mechanism is used instead of the standard Java object serialization that is lacking in MIDP. In this architecture, XML is used to transmit object data.The mobile end-to-end security protocol has the main design issues of maintainability and extensibility. Cryptographic operations are performed with a free library, Bouncy Castle Cryptography Package. The object-oriented architecture of the protocol implementation makes the replacement of this library with another cryptography package easier.Mobile end-to-end security protocol is tested with a mobile hospital reservation system application. Test cases are prepared to measure the performance of the protocol implementation with different cipher suites and platforms. Measured values of all handshake operation and defined time spans are given in tables and compared with graphs.
Estimation of Low Sucrose Concentrations and Classification of Bacteria Concentrations With Machine Learning on Spectroscopic Data
(Izmir Institute of Technology, 2019-06) Mezgil, Bahadır; Baştanlar, Yalın; 03.04. Department of Computer Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Spectroscopy can be used to identify elements. In a similar way, there are recent studies that use optical spectroscopy to measure the material concentrations in chemical solutions. In this study, we employ machine learning techniques on collected ultraviolet-visible spectra to estimate the level of sucrose concentrations in solutions and to classify bacteria concentrations. Some metal nanoparticles are very sensitive to refraction index changes in the environment and this helps to detect small refraction index changes in the solution. In our study, gold nanoparticles are used and we benefited from this property to estimate sucrose concentrations. The samples in different low sucrose concentration solutions are obtained by mixing the sucrose measured with precision scales with pure water and then the UV-Vis spectrum of each sample is measured. For the bacteria concentration solutions, spectra for six different bacteria concentrations are captured. Spectra of the same solutions are also captured before adding the bacteria. For each of these solutions, four sets are prepared where gold nanoparticles are not grown (minute 0) and grown for 4 minutes, 10 minutes and 12 minutes. After the dataset preparation, these spectrum measurements are transferred into MATLAB environment as sucrose concentration dataset and bacteria solution dataset. Then the necessary preprocessing steps are performed in order to get the most informative and distinguishing information from these datasets. The raw measurement values and processed spectrum measurements are trained with shallow Artificial Neural Networks (ANN) on MATLAB Deep Learning Toolbox and Support Vector Machine (SVM) on MATLAB Statistics and Machine Learning Toolbox. When the results of the conducted machine learning experiments are examined, success rate is promising for the estimation of sucrose concentrations and very high for classification of bacteria concentrations in pure water solution.

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