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Article Citation - WoS: 18Citation - Scopus: 24Fusion of Smartphone Sensor Data for Classification of Daily User Activities(Springer, 2021) Sengul, Gokhan; Ozcelik, Erol; Misra, Sanjay; Damasevicius, Robertas; Maskeliunas, RytisNew mobile applications need to estimate user activities by using sensor data provided by smart wearable devices and deliver context-aware solutions to users living in smart environments. We propose a novel hybrid data fusion method to estimate three types of daily user activities (being in a meeting, walking, and driving with a motorized vehicle) using the accelerometer and gyroscope data acquired from a smart watch using a mobile phone. The approach is based on the matrix time series method for feature fusion, and the modified Better-than-the-Best Fusion (BB-Fus) method with a stochastic gradient descent algorithm for construction of optimal decision trees for classification. For the estimation of user activities, we adopted a statistical pattern recognition approach and used the k-Nearest Neighbor (kNN) and Support Vector Machine (SVM) classifiers. We acquired and used our own dataset of 354 min of data from 20 subjects for this study. We report a classification performance of 98.32 % for SVM and 97.42 % for kNN.Article Citation - WoS: 10Citation - Scopus: 12Secondary-Task Effects on Learning With Multimedia: an Investigation Through Eye-Movement Analysis(Routledge Journals, Taylor & Francis Ltd, 2017) Acarturk, Cengiz; Ozcelik, ErolThis study investigates secondary-task interference on eye movements through learning with multimedia. We focus on the relationship between the influence of the secondary task on the eye movements of learners, and the learning outcomes as measured by retention, matching, and transfer. Half of the participants performed a spatial tapping task while studying the instructional materials, whereas the other half studied the materials, without spatial tapping. The results revealed suboptimal learning outcomes under the secondary task, which was accompanied by fewer transitions of gaze between the text and the figure. We propose that the suboptimal learning outcomes might be due to the disrupted processing of pictures, and possibly due to the less efficient integration, of the information gathered from the text and figures.Article Citation - WoS: 3Citation - Scopus: 4Attention Mediates the Effect of Emotional Arousal on Learning Outcomes in Multimedia Learning: an Eye-Tracking Study(Routledge Journals, Taylor & Francis Ltd, 2023) Aksaray, Sevgi Genc; Ozcelik, ErolRecent findings from psychological studies have shown that emotional arousal improves human memory. However, more evidence is necessary if these results are generalisable to multimedia learning environments. Considering these needs, the study has the goal to examine the effect of emotional arousal on multimedia learning. Fifty-seven participants were presented with instructional materials with either high- or low-arousing words and pictures in an experimental study. The eye movements of participants were recorded while they studied the instructional materials to examine the online processes during learning. The results suggest that emotional arousal enhanced recall and transfer scores. The eye-tracking results demonstrate that emotional arousal attracted attention. The results of the mediation analysis suggest that fixation time on emotional pictures as an indicator of attention mediated the relationship between emotional arousal and learning outcomes. The findings show the importance of the guidance of attention by emotional multimedia elements for learning.Article Citation - WoS: 8Citation - Scopus: 7The Underlying Reasons of the Navigation Control Effect on Performance in a Virtual Reality Endoscopic Surgery Training Simulator(Taylor & Francis inc, 2019) Cagiltay, Nergiz Ercil; Ozcelik, Erol; Berker, Mustafa; Dalveren, Gonca Gokce MenekseNavigation control skills of surgeons become very critical for surgical procedures. Strategies improving these skills are important for developing higher-quality surgical training programs. In this study, the underlying reasons of the navigation control effect on performance in a virtual reality-based navigation environment are evaluated. The participants' performance is measured in conditions: navigation control display and paper-map display. Performance measures were collected from 45 beginners and experienced residents. The results suggest that navigation display significantly improved performance of the participants. Also, navigation was more beneficial for beginners than experienced participants. The underlying reason of the better performance in the navigation condition was due to lower number of looks to the map, which causes attention shifts between information sources. Accordingly, specific training scenarios and user interfaces can be developed to improve the navigation skills of the beginners considering some strategies to lower their number of references to the information sources.Article Citation - WoS: 11Citation - Scopus: 13Gesture-Based Interaction for Learning: Time To Make the Dream a Reality(Wiley, 2012) Ozcelik, Erol; Sengul, Gokhan[No Abstract Available]Article Citation - WoS: 21Citation - Scopus: 30Quantification of the Effects of Transcutaneous Electrical Nerve Stimulation With Functional Magnetic Resonance Imaging: a Double-Blind Randomized Placebo-Controlled Study(W B Saunders Co-elsevier inc, 2010) Kara, Murat; Ozcakar, Levent; Gokcay, Didem; Ozcelik, Erol; Yorubulut, Mehmet; Guneri, Sinem; Cetin, AlpObjective: To evaluate the effects of transcutaneous electric nerve stimulation (TENS) by using functional magnetic resonance imaging (fMRI) in patients with carpal tunnel syndrome (CTS). Design: Randomized controlled trial. Settings: University medical center and an outpatient imaging center. Participants: Female patients with CTS (n=20) were randomized into 2 groups receiving either TENS (n=10) or sham TENS (n=10). In both groups, an initial baseline fMRI session was performed via stimulating digits 2, 5, and 3 in turn, I scan run for each. TENS versus sham TENS treatment was given, and a repeat imaging was performed starting 20 minutes after the treatment as follows: second finger on the 20th minute, fifth finger on the 25th minute (ulnar nerve innervated control finger), and third finger on the 30th min. Interventions: Not applicable. Main Outcome Measure: Differences in fMRI activation between the 2 groups were evaluated. Results: Our results demonstrated that 20 to 25 minutes after TENS treatment-but not in the sham TENS group-a significant fMRI signal decrease for digit 2 (post-TENS vs baseline) was observed in the secondary somatosensory regions, ipsilateral primary motor cortex (M1), contralateral supplementary motor cortex (SMA), contralateral parahippocampal gyrus, contralateral lingual gyrus, and bilateral superior temporal gyrus. Measurements on the 25th to 30th minutes for digit 5 were similar between the groups, with presence of activities in areas other than generally activated regions because of painful stimuli. Thirty to 35 minutes after TENS treatment, a significant fMRI signal decrease for digit 3 was detected in the contralateral M1 and contralateral SMA only in the TENS group. Conclusions: Our findings showed that TENS treatment significantly decreased the pain-related cortical activations caused by stimulation of the median nerve innervated fingers up to 35 minutes after treatment.Article Citation - WoS: 15Citation - Scopus: 15Construct and Face Validity of the Educational Computer-Based Environment (ece) Assessment Scenarios for Basic Endoneurosurgery Skills(Springer, 2017) Cagiltay, Nergiz Ercil; Ozcelik, Erol; Sengul, Gokhan; Berker, MustafaBackground In neurosurgery education, there is a paradigm shift from time-based training to criterion-based model for which competency and assessment becomes very critical. Even virtual reality simulators provide alternatives to improve education and assessment in neurosurgery programs and allow for several objective assessment measures, there are not many tools for assessing the overall performance of trainees. This study aims to develop and validate a tool for assessing the overall performance of participants in a simulation-based endoneurosurgery training environment. Methods A training program was developed in two levels: endoscopy practice and beginning surgical practice based on four scenarios. Then, three experiments were conducted with three corresponding groups of participants (Experiment 1, 45 (32 beginners, 13 experienced), Experiment 2, 53 (40 beginners, 13 experienced), and Experiment 3, 26 (14 novices, 12 intermediate) participants). The results analyzed to understand the common factors among the performance measurements of these experiments. Then, a factor capable of assessing the overall skill levels of surgical residents was extracted. Afterwards, the proposed measure was tested to estimate the experience levels of the participants. Finally, the level of realism of these educational scenarios was assessed. Results The factor formed by time, distance, and accuracy on simulated tasks provided an overall performance indicator. The prediction correctness was very high for the beginners than the one for experienced surgeons in Experiments 1 and 2. When non-dominant hand is used in a surgical procedure-based scenario, skill levels of surgeons can be better predicted. The results indicate that the scenarios in Experiments 1 and 2 can be used as an assessment tool for the beginners, and scenario-2 in Experiment 3 can be used as an assessment tool for intermediate and novice levels. It can be concluded that forming the balance between perceived action capacities and skills is critical for better designing and developing skill assessment surgical simulation tools.
