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Master Thesis Milimetre Dalga Bandında Bina İçi İnsan Yoğun Ortamlarda Sinyal Seviyesi Değişkenliğinin Ölçümü ve Modellenmesi(2021) Benzaghta, Mohamed; Kara, AliMilimetre dalga spektrumu, beşinci nesil (5G) kablosuz teknoloji için en temel bileşendir. Milimetre dalga bandındaki radyo kanallarında insan vücudu önemli kesinti sebebi ve sinyal değişkenliği nedenidir. Bu tez çalışmasında, 28 GHz bandında 3 farklı insan modeli ile insan vücudunun sinyal kesintisine ve zayıflamasına etkisine yönelik ölçümler sunulmaktadır. Ayrıca farklı alıcı-verici anten yüksekliklerine göre insan vücudu yerleşiminin etkisi de incelenmektedir. Farklı boyutlarda insan vücutları ve yerleşimleri ile anten yükseklikleri dikkate alınarak Fresnel kırınım modelinin en iyi çalışan model olduğu gösterilmektedir. Ayrıca Fresnel kırınım modeli ile Geometrik Kırınım Teorisi (GKT) modellerini de kıyaslanmakta, öncekinin daha doğru ve gerçeklenmesi basit olduğu gösterilmektedir. İlave olarak tez çalışmasında, insan yoğunluğunun milimetre dalga yayılımında kesinti süresi ve derinliğine yönelik istatistiklerde ölçümler yoluyla çıkarılmaktadır. Bu kapsamda, 3 ve 6 kişinin bir ofis ortamında olağan günlük hareket rotaları dikkate alınarak radyo linkini kesmesine yönelik istatistikler ilk defa bu tez çalışmasında sunulmaktadır.Article Citation - WoS: 3Citation - Scopus: 3Modeling and Measurement of Human Body Blockage Loss at 28 Ghz(Taylor & Francis Ltd, 2023) Benzaghta, Mohamed; Gokdogan, Bengisu Yalcinkaya; Coruk, Remziye Busra; Kara, AliMillimeter-wave (mm-Wave) spectrum is an essential enabler to the fifth generation (5G) wireless technology. Humans are one of the most noticeable blockers that cause temporal variation in indoor radio channels. This paper presents human blockage measurements at 28 GHz, with several humans of different sizes. The effect of the crossing orientations of the human bodies is investigated for three different transmitter heights. A human blockage model based on the Fresnel diffraction scheme is shown to be applicable in estimating the human blockage loss in indoor radio links considering various body sizes, different crossing orientations, and different transmitter heights. The findings reported in this paper could help improve indoor radio channel models at 28 GHz bands for 5G technologies considering the presence of human body blockages.Article Citation - Scopus: 1A Hybrid-Flipped Classroom Approach: Students' Perception and Performance Assessment(Univ Nac Colombia, Fac ingenieria, 2023) Gokdogan, Bengisu Yalcinkaya; Coruk, Remziye Busra; Benzaghta, Mohamed; Kara, AliThis study presents an improved hybrid-flipped classroom (hybrid-FC) education method based on technology-enhanced learning (TEL) along with diluted classes for a course on probability and random processes in engineering. The proposed system was implemented with the participation of two student groups who alternated weekly between attending face-to-face activities and fully online classes as a sanitary measure during the pandemic. The education model was combined with the flipped classroom (FC) approach in order to improve the quality of learning and address the negative effects of remote education. Before the lessons, the students studied the course material, filled a question form, and then took a low- stake online quiz. Then, the students attended a session where the questions reported in the forms were discussed, and they took an online problem-solving session followed by an individual quiz. Class sessions were available to both online and face-to-face students, as well as in the form of video recordings for anyone who missed lessons. Qualitatively and quantitatively, the proposed education method proved to be more effective and comprehensive than conventional online methodologies. The students' performances were evaluated via quizzes and exams measuring the achievement of the course learning outcomes ( CLOs). Weekly pre/post-tests were applied to examine the students' progress in each topic. Midterm and final exams were planned to measure the level of success for all course topics. Additionally, the students' perception was assessed with questionnaires and face-to-face interviews. A performance assessment showed an apparent increase in the success rate, and the students' perception was found to be positive.