Does continuous assessment using rubrics help to uncover unexpected gaps in student understanding?

Poster presentation at the NAIRTL National Academy 2nd Annual Conference, 13-14 November, 2008, Waterford Institute of Technology, IrelandModule EE4011, “Radio Frequency Integrated Circuit Design”, an optional final-year module in the B.E. (Electrical) programme at UCC, incorporates a computer-based assignment which accounts for 20% of the final marks. In 2007/8, a detailed marking scheme in the form of a rubric was given to the students with the assignment to allow them to clearly see where effort should be expended in the assignment itself and in the written report on which the marks would be based. The final grades for the continuous assessments were determined by systematically evaluating how closely each student had met the standards of performance as specified in the rubric. By concentrating on the rubric for the purposes of evaluation, the assessor was not as distracted by small errors or misconceptions in the student reports as could possibly occur when grading the reports without the help of the detailed rubric. In fact, by concentrating on the rubric for grading purposes, the assessor felt a certain leeway to reevaluate the reports from a student learning perspective in order to gain insights into minor misconceptions which occasionally appeared. These minor misconceptions could subsequently be clarified in a follow-up tutorial. Thus, the rubric-based approach, while primarily targeted in this instance at determining a grade, created clarity at grading time and allowed a separation between the task of grading and the search for misconceptions which could hinder student learning, with the latter being an unexpected but welcome bonus

An educational tool for RF LNA analysis based on an implementation of the Smith Chart in Excel

This paper describes a simple tool for the analysis and design of single-stage Radio Frequency Low Noise Amplifiers based on standard Smith-Chart procedures that has been implemented in Excel. The tool allows the user to enter the transistor's s-parameters and details of the source and load networks and to interactively explore the effects of these quantities on design variables such as gain, noise figure and stability. It also facilitates the design of two-element matching networks to transform the source and load impedances to optimum values to achieve the desired gain and noise performance

Promoting integrative learning through student assignments

Poster presentation at the NAIRTL National Academy 3nd Annual Conference, 11-12 November 2009, Trinity College Dublin, IrelandThis poster reports on an investigation with students taking a design course in a final-year Bachelor of Engineering programme to test the hypothesis that “careful selection of the continuous assessment topic will lead to an integrative learning experience for the students, helping to unify the different strands of the module and developing the students’ capabilities to apply their knowledge to new situations beyond the classroom environment”. The course investigated in this study, “Radio Frequency Integrated Circuit Design”, incorporates a continuous assessment element which contributes 20% to the final module grade. In previous years the continuous assessment was based around the use of a Computer Aided Design tool used to perform detailed simulations of a circuit block that had been introduced in class. For the 2008/9 academic year, the continuous assessment was based around a technical research paper which incorporated some elements that had been previously discussed in class but also incorporated some elements not seen previously by the students. In this way, the students were challenged by a new application scenario for their knowledge while at the same time being encouraged to see how the different strands of the module could be combined to form a useful commercial product as outlined in the research paper. This paper outlines how different elements of integrative learning such as an emphasis on real world problems, an emphasis on the interconnections between the course topics, the incorporation of a student seminar (student as teacher) and the use of reports and feedback were incorporated into the continuous assessment component of the design module. It presents the results of a questionnaire designed to uncover the students’ own opinions about their learning and provides an overall review of the investigation to identify the strategies that helped to promote integrative learning with a view to further developing these for future years

The detuning effects of a wrist-worn antenna and design of a custom antenna measurement system

This paper investigates the effects of antenna detuning on wireless devices caused by the presence of the human body,particularly the wrist. To facilitate repeatable and consistent antenna impedance measurements, an accurate and low cost human phantom arm, that simulates human tissue at 433MHz frequencies, has been developed and characterized. An accurate and low cost hardware prototype system has been developed to measure antenna return loss at a frequency of 433MHz and the design, fabrication and measured results are presented. This system provides a flexible means of evaluating closed-loop reconfigurable antenna tuning circuits for use in wireless mote applications

Antenna tuning for wearable wireless sensors

When miniaturized wireless sensors are placed on or close to the human body, they can experience a significant loss inperformance due to antenna detuning, resulting in degradationof wireless performance as well as decreased battery lifetime.Several antenna tuning technologies have been proposed formobile wireless devices but devices suitable for widespread integration have yet to emerge. This paper highlights the possible advantages of antenna tuning for wearable wireless sensors and presents the design and characterization of a prototype 433MHz tuner module

Development and evaluation of an RF Vector Network Analyser experiment for an undergraduate engineering programme

This paper outlines the development of an RF Vector Network Analyser (VNA) laboratory for undergraduate electronic engineering students. Because of the expense of high-quality high-frequency vector network analyser systems, these are usually only encountered by a small number of students who undertake a senior-year project in the RF/microwave area. This paper describes a VNA-based laboratory which is intended to be used by all undergraduate Electrical and Electronic Engineering students in the 4th year of the programme, thus giving all students an insight into this sometimes “mysterious” area of the undergraduate curriculum. The paper moves from the initial “wish list” for what the laboratory might incorporate to the final roll-out to a cohort of 23 students. Feedback from the students indicate that the laboratory session was well received while also indicating that there is potential for improvement in some areas

On the Double Planet System Around HD 83443

The Geneva group has reported two Saturn-mass planets orbiting HD 83443 (K0V) with periods of 2.98 and 29.8 d. The two planets have raised interest in their dynamics because of the possible 10:1 orbital resonance and the strong gravitational interactions. We report precise Doppler measurements of HD 83443 obtained with the Keck/HIRES and the AAT/UCLES spectrometers. These measurements strongly confirm the inner planet with period of 2.985 d, with orbital parameters in very good agreement with those of the Geneva group. However these Doppler measurements show no evidence of the outer planet, at thresholds of 1/4 (3 m/s) of the reported velocity amplitude of 13.8 m/s. Thus, the existence of the outer planet is in question. Indeed, the current Doppler measurements reveal no evidence of any second planet with periods less than a year.Comment: 26 pages incl. 3 tables and 8 figures; uses AASTE

A dual-ISM-band antenna of small size using a spiral structure with parasitic element

This letter presents a compact, single-feed, dual-band antenna covering both the 433-MHz and 2.45-GHz Industrial Scientific and Medical (ISM) bands. The antenna has small dimensions of 51 ×28 mm². A square-spiral resonant element is printed on the top layer for the 433-MHz band. The remaining space within the spiral is used to introduce an additional parasitic monopole element on the bottom layer that is resonant at 2.45 GHz. Measured results show that the antenna has a 10-dB return-loss bandwidth of 2 MHz at 433 MHz and 132 MHz at 2.45 GHz, respectively. The antenna has omnidirectional radiation characteristics with a peak realized gain (measured) of -11.5 dBi at 433 MHz and +0.5 dBi at 2.45 GHz, respectively

Design of a compact, fully-autonomous 433 MHz tunable antenna for wearable wireless sensor applications

The authors present the design of a tunable 433 MHz antenna that is tailored for wearable wireless sensor applications. This study first presents a detailed analysis of the measured impedance characteristics of a chosen antenna under test (AUT) in varying proximity to a human test subject. Instead of limiting the analysis to the head and hand only, this analysis measures the AUT impedance at varying distances from 11 different body positions. A novel antenna equivalent circuit model is then developed that enables both the free-space and total on-body AUT impedance variation to be rapidly computed using a circuit simulator instead of the requirement for computationally intensive finite-element methods for example. The design and characterisation of a tunable matching network that enables AUT impedance matching for 11 different positions on the human body is then outlined. Finally, a fully-autonomous 433 MHz tunable antenna is demonstrated. The antenna occupies a small printed circuit board area of 51 × 28 mm and is printed on standard FR-4 material with the tuner completely integrated into the antenna itself. Prototype measurements show an improvement of 3.9 dB in power delivery to the antenna for a load voltage standing wave ratio of 17:1, with a maximum matching loss of 0.84 dB and S 11 (−10 dB) ≥ 18 MHz for all load conditions

Optical and Near-Infrared Observations of the Peculiar Type Ia Supernova 1999ac

We present 39 nights of optical photometry, 34 nights of infrared photometry, and 4 nights of optical spectroscopy of the Type Ia SN 1999ac. This supernova was discovered two weeks before maximum light, and observations were begun shortly thereafter. At early times its spectra resembled the unusual SN 1999aa and were characterized by very high velocities in the Ca II H and K lines, but very low velocities in the Si II 6355 A line. The optical photometry showed a slow rise to peak brightness but, quite peculiarly, was followed by a more rapid decline from maximum. Thus, the B- and V-band light curves cannot be characterized by a single stretch factor. We argue that the best measure of the nature of this object is not the decline rate parameter Delta m_15 (B). The B-V colors were unusual from 30 to 90 days after maximum light in that they evolved to bluer values at a much slower rate than normal Type Ia supernovae. The spectra and bolometric light curve indicate that this event was similar to the spectroscopically peculiar slow decliner SN 1999aa.Comment: 42 pages, 14 figures, accepted for publication in the Astronomical Journal (January 28, 2006