Gender in Engineering Departments: Are There Gender Differences in Interruptions of Academic Job Talks?

We use a case study of job talks in five engineering departments to analyze the under-studied area of gendered barriers to finalists for faculty positions. We focus on one segment of the interview day of short-listed candidates invited to campus: the “job talk”, when candidates present their original research to the academic department. We analyze video recordings of 119 job talks across five engineering departments at two Research 1 universities. Specifically, we analyze whether there are differences by gender or by years of post-Ph.D. experience in the number of interruptions, follow-up questions, and total questions that job candidates receive. We find that, compared to men, women receive more follow-up questions and more total questions. Moreover, a higher proportion of women’s talk time is taken up by the audience asking questions. Further, the number of questions is correlated with the job candidate’s statements and actions that reveal he or she is rushing to present their slides and complete the talk. We argue that women candidates face more interruptions and often have less time to bring their talk to a compelling conclusion, which is connected to the phenomenon of “stricter standards” of competence demanded by evaluators of short-listed women applying for a masculine-typed job. We conclude with policy recommendations

Perceptual video quality optimization in AWGN channel using low complexity channel code rate allocation

ABSTRACT In error-prone channels, forward error correction is necessary for protecting important data. In this paper, we use a packet loss visibility model to evaluate the visual importance of video packets to be transmitted. With the loss visibility of each packet, we use the Branch and Bound method to optimally allocate rates of Rate-Compatible Punctured Convolutional codes. The complexity of our prior algorithm can be reduced by k-means clustering before using the Branch and Bound method. Experimental results show that the proposed unequal error protection algorithm can improve upon the received video quality compared to our prior work with much lower complexity. Index Terms-Unequal error protection, packet loss visibility model, perceptual quality

Robust Deep Sensing Through Transfer Learning in Cognitive Radio

We propose a robust spectrum sensing framework based on deep learning. The received signals at the secondary user's receiver are filtered, sampled and then directly fed into a convolutional neural network. Although this deep sensing is effective when operating in the same scenario as the collected training data, the sensing performance is degraded when it is applied in a different scenario with different wireless signals and propagation. We incorporate transfer learning into the framework to improve the robustness. Results validate the effectiveness as well as the robustness of the proposed deep spectrum sensing framework

Uplink Resource Management for Multiuser OFDM Video Transmission Systems: Analysis and Algorithm Design

We consider a multiuser OFDM system in which users want to transmit videos via a base station. The base station knows the channel state information (CSI) as well as the rate distortion (RD) information of the video streams and tries to allocate power and spectrum resources to the users according to both physical layer CSI and application layer RD information. We derive and analyze a condition for the optimal resource allocation solution in a continuous frequency response setting. The optimality condition for this cross layer optimization scenario is similar to the equal slope condition for conventional video multiplexing resource allocation. Based on our analysis, we design an iterative subcarrier assignment and power allocation algorithm for an uplink system, and provide numerical performance analysis with different numbers of users. Comparing to systems with either only physical layer or only application layer information available at the base station, our results show that the user capacity and the video PSNR performance can be increased significantly by using cross layer design. Bit-level simulations which take into account the imperfection of the video coding rate control, the variation of RD curve fitting, as well as channel errors, are presented

Cross layer resource allocation design for uplink video OFDMA wireless systems

Abstract-We study an uplink video communication system with multiple users in a centralized wireless cell. The multiple access scheme is Orthogonal Frequency Division Multiple Access (OFDMA). Both physical layer channel state information (CSI) and application layer rate distortion (RD) information of video streams are collected by the base station. With the goal of minimizing the average video distortion across all the users in the system, we design an iterative resource allocation algorithm for subcarrier assignment and power allocation. Based on the physical layer resource allocation decision, the user will adapt the application layer video source coding rate. To show the advantage of this cross layer algorithm, numerical results are compared with two baseline resource allocation algorithms using only physical layer information or only application layer information. Bit-level simulation results are presented which take into account the imperfection of the video coding rate control, as well as channel errors. Index Terms-Cross layer design, multiuser video communications system, OFDMA, video multiplexing

Vector quantization of image subbands: a survey

Subband and wavelet decompositions are powerful tools in image coding because of their decorrelating effects on image pixels, the concentration of energy in a few coefficients, their multirate/multiresolution framework, and their frequency splitting, which allows for efficient coding matched to the statistics of each frequency band and to the characteristics of the human visual system. Vector quantization (VQ) provides a means of converting the decomposed signal into bits in a manner that takes advantage of remaining inter and intraband correlation as well as of the more flexible partitions of higher dimensional vector spaces. Since 1988, a growing body of research has examined the use of VQ for subband/wavelet transform coefficients. We present a survey of these methods

Resource Allocation and Performance Analysis for Multiuser Video Transmission over Doubly Selective Channels

We consider an uplink multicarrier system with multiple video users who want to send compressed video data to the base station. In the time domain, we model the time varying channel using Jakes’ model, and in the frequency domain, each subcarrier is assumed to be independently fading. The video is scalably coded in units of group of pictures (GOP), and users have different video rate distortion (RD) functions. At the beginning of the GOP, the base station collects both the RD information and instantaneous channel state information (CSI) for subcarrier allocation purposes. We design a cross layer resource allocation algorithm to assign subcarriers to the users based on both the demand of the video and the quality of the channel. Once the resource allocation decision is made, the users then periodically adapt the modulation format of the subcarriers allocated according to the evolution of the CSI for the duration of the GOP. We show that our cross layer resource allocation robustly outperforms two baseline algorithms, each of which uses only one layer of information for resource allocation