WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
Browse
19 results
Search Results
Now showing 1 - 10 of 19
Conference Object Citation - WoS: 4Citation - Scopus: 12Event Oriented Vs Object Oriented Analysis for Microservice Architecture: an Exploratory Case Study(Institute of Electrical and Electronics Engineers, 2021) Ünlü, Hüseyin; Tenekeci, Samet; Yıldız, Ali; Demirörs, OnurThe rapidly developing internet infrastructure together with the advances in software technology has enabled the development of cloud-based modern web applications that are much more responsive, flexible, and reliable compared to traditional monolithic applications. Such modern applications require new software design paradigms and architectures. Microservice-based architecture (MSbA), which aims to create small, isolated, loosely-coupled applications that work in cohesion, becoming widespread as one of these approaches. MSbA allows the developed applications to be deployed and maintained separately, as well as scaled on demand. However, there is no de facto method for the analysis and design of systems for these architectures. In this paper, we compared the usefulness of the object-oriented (OO) and event-oriented (EO) approaches for analyzing and designing MS-based systems. More specifically, we performed an exploratory case study to analyze, design, and implement a software application dealing with the 'application and evaluation process of graduate students at IzTech'. This paper discusses the results of this case study. We observe that the EO approaches have significant advantages with respect to the OO approaches.Conference Object Investigation of In-Gap Field Enhancement at Terahertz Frequencies for a Metasurface Enhanced Sensor(Institute of Electrical and Electronics Engineers, 2021) Tugay, Halime; Altan, Hakan; Demirhan, Yasemin; Özyüzer, Lütfi; Sabah, CumaliThe arrangements of subwavelength inclusions in a metasurface can serve as an effective absorber for the terahertz region. When such an absorber is combined with a unique material, the absorption can induce effects that can lead to a change in the materials electrical properties. Vanadium dioxide shows a passive and reversible change from monoclinic insulator phase to metallic tetragonal rutile structure by using external stimuli such as temperature (340K), photo excitation, electric field, mechanical strain or magnetic field [1,2]. Upon absorption of the THz radiation, the high electric fields that are generated inside the gaps of the metasurface can serve as trigger points, as was shown previously using kV strength THz E-fields.Conference Object Citation - WoS: 4Citation - Scopus: 5Code Change Sniffer: Predicting Future Code Changes With Markov Chain(Institute of Electrical and Electronics Engineers, 2021) Ufuktepe, Ekincan; Tuğlular, TuğkanCode changes are one of the essential processes of software evolution. These changes are performed to fix bugs, improve quality of software, and provide a better user experience. However, such changes made in code could lead to ripple effects that can cause unwanted behavior. To prevent such issues occurring after code changes, code change prediction, change impact analysis techniques are used. The proposed approach uses static call information, forward slicing, and method change information to build a Markov chain, which provides a prediction for code changes in the near future commits. For static call information, we utilized and compared call graph and effect graph. We performed an evaluation on five open-source projects from GitHub that varies between 5K-26K lines of code. To measure the effectiveness of our proposed approach, recall, precision, and f-measure metrics have been used on five open-source projects. The results show that the Markov chain that is based on call graph can have higher precision compared to effect graph. On the other hand, for small number of cases higher recall values are obtained with effect graph compared to call graph. With a Markov chain model based on call graph and effect graph, we can achieve recall values between 98%-100%. © 2021 IEEE.Conference Object A New Continuous Velocity Observer Formulation for a Class of Uncertain Nonlinear Mechanical Systems(Institute of Electrical and Electronics Engineers, 2015) Bayrak, Alper; Tatlıcıoğlu, Enver; Zergeroǧlu, Erkan; Deniz, MeryemIn this study, we present a smooth robust velocity observer for a class of uncertain nonlinear mechanical systems. The smoothness of the observers is guaranteed by utilizing hyperbolic tangent function as opposed to signum-type functions applied in most robust and sliding mode observers found in the literature. The proposed observer does not require a priori knowledge of an upper bound of the uncertain system dynamics and introduces a time-varying observer gain for uncertainty compensation. Practical stability of the observer error is ensured via Lyapunov-type stability analysis. Numerical simulation studies backed up by experimental results are presented to illustrate the performance of the proposed observer.Conference Object Citation - WoS: 3Citation - Scopus: 6Truth Ratios of Syllogistic Moods(Institute of Electrical and Electronics Engineers, 2015) Zarechnev, Mikhail; Kumova, Bora İsmailThe syllogistic system consists of 256 moods, of which only 24 have been recognized as true. From a set-theoretical point of view, a mood can be represented with three sets and their possible relationships. Three sets can have up to seven sub-sets or spaces. In an earlier work we have used 41 permutations of the spaces, out of which every mood matches an individual number as true or false cases. The truth ratio of a mood is then calculated, by relating the true and false cases with each other. In this work we revise the previously presented properties of the moods and the syllogistic system, this time by using the maximum possible cover, which consists of 96 distinct space permutations. Our results mostly verify our previous findings, like the additional true mood anasoy, the inherently symmetric truth distribution of the moods. Additionally we have revealed some new properties, like the equivalence of some moods, which reduces the system to 136 distinct moods.Conference Object Citation - WoS: 10Citation - Scopus: 12Random Test Generation From Regular Expressions for Graphical User Interface (gui) Testing(Institute of Electrical and Electronics Engineers, 2019) Kılınççeker, Onur; Silistre, Alper; Challenger, Moharram; Belli, FevziGeneration of test sequences, that is, (user) inputs - expected (system) outputs, is an important task of testing of graphical user interfaces (GUI). This work proposes an approach to randomly generate test sequences that might he used for comparison with existing GUI testing techniques to evaluate their efficiency. The proposed approach first models CUI under test by a finite state machine (FSM) and then converts it to a regular expression (RE). A tool based on a special technique we developed analyzes the RE to fulfill missing context information such as the position of a symbol in the RE. The result is a context table representing the RE. The proposed approach traverses the context table to generate the test sequences. To do this, the approach repeatedly selects a symbol in the table, starting from the initial symbol, in a random manner until reaching a special, finalizing symbol for constructing a test sequence. Thus, the approach uses a symbol coverage criterion to assess the adequacy of the test generation. To evaluate the approach, mutation testing is used. The proposed technique is to a great extent implemented and is available as a tool called PQ-Ran Test (PQ-analysis based Random Test Generation). A case study demonstrates the proposed approach and analyzes its effectiveness by mutation testing.Conference Object Citation - WoS: 1Citation - Scopus: 1Changes in Attention and Mental Rotation Performance in Relation To Luminance Variations in Educational Spaces(Institute of Electrical and Electronics Engineers, 2020) Öner, Merve; Kazanasmaz, Zehra TuğçeThis paper attempts to investigate attention and mental rotation performance of students under two groups of luminance ratios in the visual field during VDT work. Each experiment was conducted under daylit conditions and consisted of two trials (with and without shading device) which were carried out in one experimental session. Twenty university students were recruited as participants to perform cognitive test as well as to administer subjective evaluations in a mock-up VDT station. Luminance ratios were grouped based on the ratios between bright light and direct surroundings. Results showed that the students gave faster responses for finding the correct target when the luminance distribution was not uniform whereas the number of correct answers given was higher when the luminance distribution was uniform. Subjective sensation of visual discomfort and lighting appraisal were in the same trend, indicating uniform luminance distribution was more appreciated by the participants. Based on these findings, the study provides additional insights in the effect of luminance patterns on individuals' performance, health and wellbeing in educational buildings. © 2020 IEEE.Conference Object Citation - WoS: 1Citation - Scopus: 3Hybrid Beamforming for Secure Multiuser Mmwave Mimo Communications(Institute of Electrical and Electronics Engineers, 2020) Erdoğan, Oğulcan; Özbek, Berna; Busari, Sherif Adeshina; González, JonathanSecure communication is critical in wireless networks as the networks are prone to eavesdropping from unintended nodes. To address this challenge, physical layer security (PLS) is being employed to combat information leakage. In this paper, we present the performance evaluations based on the secrecy rate and the secrecy outage probability for multiuser multiple-input multiple-output (MIMO) millimeter-wave (mmWave) communications by employing hybrid beamforming (HBF) at the base station, legitimate users and eavesdropper. Using a 3-dimensional mmWave channel model and uniform planar antenna arrays (UPA), we employ artificial noise (AN) beamforming to jam the channels of eavesdropper and to enhance the secrecy rate. The transmitter uses the minimum mean square error (MMSE) precoder to mitigate multiuser interference for the secure MIMO mmWave systems. It is shown that the overall system performance highly depends on the power allocation factor between AN and the signal of legitimate users. © 2020 IEEE.Conference Object Citation - WoS: 7Citation - Scopus: 8Models in Graphical User Interface Testing: Study Design(Institute of Electrical and Electronics Engineers, 2020) Silistre, Alper; Kılınççeker, Onur; Belli, Fevzi; Challenger, Moharram; Kardaş, GeylaniModel-based GUI testing is an important concept in Software GUI testing. Manual testing is a time-consuming labor and heavily error-prone. It has several well-accepted models that Software Testing community has been working and contributing to them for many years. This paper reviews different models used in model-based GUI testing and presents a case study with a proposed approach for how to convert several well-accepted models to ESG (Event Sequence Graphs) to generate test cases and execute them with an aim to consolidate past and future works in a single model. © 2020 IEEE.Conference Object Citation - WoS: 1Citation - Scopus: 1Mutation Operators for Decision Table-Based Contracts Used in Software Testing(Institute of Electrical and Electronics Engineers, 2020) Khalilov, Abbas; Tuğlular, Tuğkan; Belli, FevziThe Design by Contract technique allows developers to improve source code with contracts, and testing using contracts helps to identify faults. However, the source code of the program under test is not always available. With black-box testing, it is possible to generate contracts from specifications of the software. In this paper, we apply mutation analysis on a model of a given specifications, where mutants are initially gained by applying proposed in this paper certain mutation operators on corresponding model, and then mutated specifications are examined. © 2020 IEEE.