Communication—Electron-Beam Stimulated Release of Dislocations from Pinning Sites in GaN

To achieve low leakage in GaN-based power devices and improve reliability in optoelectronic devices such as laser diodes, it is necessary to reduce dislocation density in epitaxial layers and control their introduction during processing. We have previously shown that dislocations can be introduced at room temperature in GaN. The effect of electron-beam irradiation at fixed points on the shift of such freshly introduced dislocations in GaN is reported. Dislocations can be displaced up to 10-15 µm from the beam position. We conclude the main reason limiting the dislocation travelling distance is the existence of a high number of pinning sites.

Radio frequency identification (RFID) and database- based attendance management system

Effective record and management of students and staff attendance of academic and non academic activities/events are vital for the smooth functioning of the educational system. This is still a difficult task in most institutions, particularly in Nigeria with a large number of staff and students attending different academic and non-academic functions. This is even more difficult to manage when the traditional method of paper and pen is used to record attendance, prone to errors, and in most cases lack integrity due to manual handling of the record. Electronics and Information Communications Technologies (ICT) can be deployed to help mitigate these problems and improve reliability, ease, speed, efficiency, effectiveness, and integrity of recording and managing attendance. In this work, we used Radio Frequency Identification (RFID) and database management to provide an alternative solution that addresses issues of objects (humans and non-humans) authentication, authorization, and record management with high accuracy, reliability, and integrity using RFID-Arduino technology. The system works by reading staff’s and/or student’s details stored in a unique RF tag wirelessly through theRF reader and then matched and stored the record in the system’s database. Attendancemarking was achieved by matching the scanned ID with the database record. The system was successfully implemented and tested with 10 students and staff participants with the feature of exporting the records into excel format for statistical analysis and performance evaluation.

Qualitative Coding in the Computational Era: A Hybrid Approach to Improve Reliability and Reduce Effort for Coding Ethnographic Interviews

Sociologists have argued that there is value in incorporating computational tools into qualitative research, including using machine learning to code qualitative data. Yet standard computational approaches do not neatly align with traditional qualitative practices. The authors introduce a hybrid human-machine learning approach (HHMLA) that combines a contemporary iterative approach to qualitative coding with advanced word embedding models that allow contextual interpretation beyond what can be reliably accomplished with conventional computational approaches. The results, drawn from an analysis of 87 human-coded ethnographic interview transcripts, demonstrate that HHMLA can code data sets at a fraction of the effort of human-only strategies, saving hundreds of hours labor in even modestly sized qualitative studies, while improving coding reliability. The authors conclude that HHMLA may provide a promising model for coding data sets where human-only coding would be logistically prohibitive but conventional computational approaches would be inadequate given qualitative foci.

Relay Selection-and-Jamming Scheme with Nonlinear Energy Harvesting

When direct source-destination communications are in outage, relay selection is a preferable solution to improve reliability for this communications. However, such a relay selection makes the eavesdropper better overhear source data through both source-relay and relay-destination communication hops, losing data security. To improve both reliability and security, this paper proposes a relay selection-and-jamming (RaJ) scheme to select one intermediate node as a conventional relay and another node as a jammer. To enhance energy efficiency, all intermediate nodes harvest radio frequency energy in source signals for their operations with nonlinear energy harvesting (NL-EH). The security and reliability of the RaJ scheme are assessed through suggested rigorous/asymptotic expressions and are significantly better than two benchmark schemes without neither jamming nor both relay selection and jamming. Additionally, they can be optimized with reasonable selection of specifications. Moreover, the NL property of the energy harvesters dramatically affects the reliability but negligibly degrades the security for the RaJ scheme. Furthermore, the linear EH (L-EH) is more reliable but less secure than the NL-EH.