On Channel Reciprocity to Activate Uplink Channel Training for Downlink Wireless Transmission in Tactile Internet Applications

We determine, for the first time, the requirement on channel reciprocity to activate uplink channel training, instead of downlink channel training, to achieve a higher data rate for the downlink transmission from a multi-antenna base station to a single-antenna user. We first derive novel closed-form expressions for the lower bounds on the data rates achieved by the two channel training strategies by considering the impact of finite blocklength. The performance comparison result of these two strategies is determined by the amount of channel reciprocity that is utilized in the uplink channel training. We then derive an approximated expression for the minimum channel reciprocity that enables the uplink channel training to outperform the downlink channel training. Through numerical results, we demonstrate that this minimum channel reciprocity decreases as the blocklength decreases or the number of transmit antennas increases, which shows the necessity and benefits of activating the uplink channel training for short-packet communications with multiple transmit antennas. This work provides pivotal and unprecedented guidelines on choosing channel training strategies and channel reciprocity calibrations, offering valuable insights into latency reduction in the Tactile Internet applications.Comment: 6 pages, 3 figures, Submitted to IEEE ICC 2018 Worksho

Constructing and Applying Rubrics in College-Level EFL Writing Assessment in China

Assessment is a critical component in the teaching of writing and plays an important role in discovering and helping to address students’ writing difficulties. Therefore, it is essential for teachers to approach writing assessment in a reliable and valid way. Previous studies showed that assessment rubrics, used as a standard to describe performance evaluation, can help teachers effectively assess student writing. The reliability and validity of the use of rubrics for helping teachers in assessing writing fairly and improving students’ writing ability has received much research attention; however, less attention has been paid to teacher training in the area of rubric construction and use. This study examined the use of and attitudes towards rubrics in college level EFL writing classes in China and the effects of teacher training in the design and application of rubrics. The data for this study were drawn from Chinese college-level English teachers as well as first- and second-year undergraduate students from a medium-sized university in China, targeting the following: (1) investigating the current writing assessment method adopted in college EFL classes in a university in China and the current situation of teacher training, examined through pre-study questionnaires, (2) conducting teacher training on rubric construction and development and examining the implementation of training through two student writing assignments, (3) examining the students’ and teachers’ attitudes towards rubric use and teachers’ attitudes towards training through post-study questionnaires. Analysis of the pre-study questionnaires indicated that, in at least the target Chinese institution, rubrics were not widely used by the college-level English teachers, and their primary focus in writing assessment was on grammatical and vocabulary errors. In addition, it appeared that in this context, the English teachers did not receive adequate training concerning the use of rubrics for writing assessment. Data collected during teacher training and application showed that after the implementation of teacher-designed rubrics as assessment tools, students’ overall and subentry writing scoring improved, though no causal relationships can be claimed. Analysis of the post-study questionnaires indicated that both students and teachers held positive attitudes towards rubrics, which they perceived as being helpful in improving writing proficiency and gaining confidence in writing. In addition, teachers also had a positive attitude towards the training. This thesis differs from previous research by combining teacher training and rubric implementation, with the focus both on teachers and students rather than only on one side. Results support the effectiveness of both rubrics in assessment and teacher training in rubric construction and use

Responsibility modulates neural mechanisms of outcome processing : an ERP study

The role of personal responsibility in decision-making and its influence on the outcome evaluation process have been investigated relatively rarely in cognitive neuroscience. The present event-related brain potential (ERP) study manipulated the subjective sense of responsibility by modifying outcome controllability in a gambling task. Participants reported a higher sense of responsibility and produced a larger fERN when they were told that the game was 'controllable' compared with when they were told that the game was 'uncontrollable.' In addition, fERN amplitude was correlatedwith individual self-reports of personal responsibility over the outcomes. These results indicate that self-attribution of responsibility associated with different degrees of controllability affects the outcome evaluation process and fERN amplitude

Performance management of event processing systems

This thesis is a study of performance management of Complex Event Processing (CEP) systems. Since CEP systems have distinct characteristics from other well-studied computer systems such as batch and online transaction processing systems and database-centric applications, these characteristics introduce new challenges and opportunities to the performance management for CEP systems. Methodologies used in benchmarking CEP systems in many performance studies focus on scaling the load injection, but not considering the impact of the functional capabilities of CEP systems. This thesis proposes the approach of evaluating the performance of CEP engines’ functional behaviours on events and develops a benchmark platform for CEP systems: CEPBen. The CEPBen benchmark platform is developed to explore the fundamental functional performance of event processing systems: filtering, transformation and event pattern detection. It is also designed to provide a flexible environment for exploring new metrics and influential factors for CEP systems and evaluating the performance of CEP systems. Studies on factors and new metrics are carried out using the CEPBen benchmark platform on Esper. Different measurement points of response time in performance management of CEP systems are discussed and response time of targeted event is proposed to be used as a metric for quality of service evaluation combining with the traditional response time in CEP systems. Maximum query load as a capacity indicator regarding to the complexity of queries and number of live objects in memory as a performance indicator regarding to the memory management are proposed in performance management of CEP systems. Query depth is studied as a performance factor that influences CEP system performance

Modeling the light curve of Type IIn-P SN 2005cl with red supergiant progenitors featuring pre-SN ourbursts

All Type IIn supernovae (SNe IIn) show narrow hydrogen emission lines in their spectra. Apart from this common feature, they demonstrate very broad diversity in brightness, duration, and morphology of their light curves, which indicates that they likely come from a variety of progenitor systems and explosion channels. A particular subset of SNe IIn, the so called SNe IIn-P, exhibit $\sim$100 days plateau phases that are very similar to the ones of the ordinary hydrogen-rich SNe (SNe II). In the past, SNe IIn-P were explained by the models of sub-energetic electron capture explosions surrounded by dense extended winds. In this work, we attempt to explain this class of SNe with standard red supergiant (RSG) progenitors that experience outbursts several month before the final explosion. The outburst energies that show the best agreement between our models and the data ($5\times10^{46}\,{\rm erg}$) fall at the low range of the outburst energies that have been observed for SNe IIn (between few times $10^{46}\,{\rm erg}$ and $10^{49}\,{\rm erg}$). Instead, the inferred explosion energy of SN 2005cl is relatively high ($1-2\times10^{51}\,{\rm erg}$) compared to the explosion energies of the ordinary SNe II. Our models provide alternative explanation of SNe IIn-P to the previously proposed scenarios.Comment: 5 pages, 3 figure