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Yayın New criteria for the existence of stable equilibrium points in nonsymmetric cellular neural networks(IEEE, 2003) Özcan, Neyir; Arık, Sabri; Tavşanoğlu, Ahmet VedatA new criteria for the existence of stable equilibrium points in nonsymmetric cellular neural networks (CNN) was presented. It was shown that the results obtained can be used to derive some complete stability conditions for some special classes of CNNs such as positive cell-linking CNNs, opposite-sign CNNs and dominant-template CNNs. The model of the CNN whose dynamical behavior was described by the state equations was discussed.Yayın Power control for fading cooperative multiple access channels(IEEE, 2007-08) Kaya, Onur; Ulukuş, ŞennurFor a fading Gaussian multiple access channel with user cooperation, we obtain the power allocation policies that maximize the average rates achievable by block Markov superposition coding, subject to average power constraints. The optimal policies result in a coding scheme that is simpler than the one for a general multiple access channel with generalized feedback. This simpler coding scheme also leads to the possibility of formulating an otherwise non-concave optimization problem as a concave one. Using the perfect channel state information available at the transmitters to adapt the powers, we demonstrate gains over the achievable rates for existing cooperative systems.Yayın Optimal nonlinear control of two-link flexible arm with adaptive internal model(2005) Doğan, Mustafa; İstefanopulos, YorgoThe control of highly nonlinear multi-link flexible arms is subject to uncertainties caused by backlash, payload changes and external disturbances.Therefore, adaptive and robust control of multi-link flexible arms is a challenging problem.In this paper, the internal model approach is adaptively tuned up for unknown disturbances, parallel with a robust stabilizer. The stabilizer part of the controller is optimized with a new evolutionary algorithm.Yayın Channel adaptive encoding and decoding strategies and rate regions for the three user cooperative multiple access channel(IEEE, 2008) Edemen, Çağatay; Kaya, OnurFor a cooperative Gaussian multiple access channel (MAC), we propose a new channel adaptive three user cooperation strategy, based on a non-trivial extension of block Markov super-position encoding. We obtain the expressions for the resulting achievable rate region. We demonstrate through simulations that the participation of an extra user in cooperation provides significant rate improvements. The proposed strategy also improves upon our earlier results on the three user cooperative MAC [1], under certain channel conditions.Yayın CMOS amplifiers for UWB applications(CRC Press-Taylor & Francis Group, 2016) Grebennikov, Andrei; Kumar, Narendra; Yarman, Bekir Sıddık Binboğa[No abstract available]Yayın The modified proactive feedback based flow control scheme for best-effort applications(International Institute of Informatics and Systemics (IIIS), 2007) Dağ, TamerHigh speed networks that are characterized by large bandwidth propagation delay products are expected to support applications with diverse traffic characteristics and Quality of Service (QoS) requirements. Thus, flow control schemes are needed for an efficient usage of the network bandwidth. A proactive feedback (PF) based flow control scheme developed by the author attempts to eliminate the bandwidth mismatch problem seen in such networks by generating and transmitting early feedbacks based on the application characteristics. In this paper, an extension of this scheme to large scale networks is presented. Due to the bottlenecked network nodes, some best effort applications may not be able to use their assigned bandwidth. For such cases, a modified version of the proactive feedback based (MPF) flow control scheme is introduced. It is observed that without affecting the other applications the best effort traffic can be significantly increased.Yayın Pre-occupancy evaluation of wayfinding signage using immersive virtual reality(Elsevier Ltd, 2025-07) Karadağ, DeryaThis study explores how alternative wayfinding signage designs influence user experience within immersive virtual environments during early-stage architectural evaluation. A 3D model of a university building's ground floor was developed and experienced through head-mounted displays (HMDs) to simulate spatial conditions. Eighteen participants completed structured navigation tasks in two signage settings, followed by post-task surveys and semi-structured interviews. Quantitative data—task completion times and circulation paths—were analysed alongside thematic evaluations of user feedback. Findings reveal that signage design affects spatial perception, navigational efficiency, and user satisfaction. The study shows that early-stage VR testing supports user-informed design decisions, especially for evaluating signage-based spatial strategies and related user experience considerations. VR emerges as a practical tool for integrating user-centred feedback into the pre-occupancy phase of spatial planning.Yayın Comparing pre-trained and fine-tuned transformer-based models for sentiment analysis in Turkish comments in student surveys(Institute of Electrical and Electronics Engineers Inc., 2025-08-15) Pourjalil, Kajal; Ekin, Emine; Recal, FüsunStudent surveys are essential for evaluating teaching quality and course content, but analyzing open-ended responses is challenging due to their unstructured and multilingual nature. This study applies sentiment analysis to Turkish educational survey responses using three transformer-based models: SAVASY, DBMDZ BERT Base Turkish Cased, and XLM-RoBERTa Base. A labeled dataset of real-world student comments was used, with sentiment labels assigned using the Gemini AI tool to facilitate model fine-tuning. Evaluation metrics included accuracy, F1-score, precision, recall, and confidence scores. Results show that fine-tuning improves sentiment classification, effectively identifying positive, negative, and neutral sentiments. This highlights the value of transformer models in analyzing Turkish student feedback.
