A nonlinear-coherence receiver

Mathematical analysis and detailed study of generic model for coherent receiver has demonstrated that nonlinear coherence between given biphase-modulated input signal and supplied reference signal can be used in receivers to improve telecommunication systems

Data-aided carrier tracking loops

Power in composite signal sidebands is used to enhance signal-to-noise ratio in carrier tracking loop, thereby reducing radio loss and decreasing probability of receiver error. By adding quadrature channel to phase-lock-loop detector circuit of receiver, dc component can be fed back into carrier tracking loop

Coherent receiver employing nonlinear coherence detection for carrier tracking

The concept of nonlinear coherence employed in carrier tracking to improve telecommunications efficiency is disclosed. A generic tracking loop for a coherent receiver is shown having seven principle feedback signals which may be selectively added and applied to a voltage controlled oscillator to produce a reference signal that is phase coherent with a received carrier. An eighth feedback signal whose nonrandom components are coherent with the phase detected and filtered carrier may also be added to exploit the sideband power of the received signal. A ninth feedback signal whose nonrandom components are also coherent with the quadrature phase detected and filtered carrier could be additionally or alternatively included in the composite feedback signal to the voltage controlled oscillator

Accessing the field : disability and the research process

Disability is as much a factor in interactional dynamics as ethnicity, age, gender or sexuality, and therefore its impact on the processes around qualitative research warrants much more systematic attention. Disabled researchers are not confined to disability studies research, although most accounts of the impact of disability on the research process have, thus far, been undertaken within this field. This paper moves beyond this narrow focus to consider the impact of disabled identities and the embodied experiences of impairment on studies involving, primarily, non-disabled people. By reflecting on our experiences as visibly disabled researchers, we highlight some of the practical, ethical and conceptual dilemmas we encountered. Impairments may assist rapport building with participants, but also introduce complex dilemmas concerning whether, when and how to disclose them, and the consequences of doing so. We highlight the centrality of the visibility of the disabled body in mediating these dilemmas, and its part in constraining our responses to them. While we value our commitment to positive readings of disability, we demonstrate that disabled researchers nevertheless undertake research in contexts where disability is assigned meanings disabled people may not share. We argue that all researchers should attend to their own ‘body signifiers’ (whether in relation to ethnicity, wealth, gender, age etc.) and embodied experiences of research processes, as these are integral to research outcomes, the ethics of research, and are a means by which to address power differentials between researcher and participant. This paper addresses a gap in the literature, using our experiences of research to highlight the negotiations and dilemmas faced by visibly disabled researchers. Negotiations of identity prompted by the disabled body in the research process require consideration and should not be ignored

Identifying Student Discussion in Computer-Mediated Problem Solving Chat

The COMPS project employs computer chat for students working in small groups solving classroom problems. This summer’s project aims to build computer classifiers that could effectively “look over the shoulders” of the students while working, to approximately recognize whether the students are engaging in productive discussion. Research questions are: can we write machine classifiers that can recognize reasoning, agreement, and disagreement in student discussions? Can we achieve this using only a common English vocabulary? Several thousand lines of COMPS transcripts were manually annotated. A topic modelling program was used to determine 10 main topics which appeared in the transcripts and the words in those topics. A Linear Classifier and a Support Vector Machine Classifier used the topic model to predict the annotation of each line of dialogue. To address the common English vocabulary research question, an intersection of many transcripts from different sources was combined with Google word lists and modified to accommodate text-chat conventions. In the normal vocabulary, we found f1 scores of 0.7 and above for reasoning. Using only common vocabulary, the scores were slightly lower. The next step is to train our topic model on a combination of transcripts and apply it to other transcripts from different student discussions

Educating and motivating adolescents who are deaf or hard of hearing with drug and alcohol addiction: Components of a curriculum that links adolescents to appropriate treatment

This paper highlights the components necessary for a drug and alcohol addiction curricula to educate, motivate, and link adolescents who are deaf or hard of hearing using oral communication to appropriate treatment

AN EVALUATION OF STOCKING AND HABITAT INFLUENCES ON CHANNEL CATFISH IN LENTIC ECOSYSTEMS OF THE GREAT PLAINS

Channel catfish Ictalurus punctatus is an important sport fish, particularly in the Great Plains. In Nebraska, a majority of anglers target channel catfish, and fishing activities are a vital part of the state’s economy. Lentic water bodies provide the primary fishing opportunity for catfish anglers in Nebraska. Despite the popularity and economic importance of channel catfish, little is known of its population dynamics or habitat requirements, and existing studies often profile river populations. Current standards for sampling channel catfish in lentic systems often yield inadequate catch to assess populations. The objective of this study was to utilize a recently developed sampling method, tandem-set hoop nets, to collect channel catfish in sufficient quantities to describe the effects of stocking and habitat variability on populations in lentic ecosystems. Three lentic ecosystems common to the Great Plains were considered: sand pits, flood-control reservoirs, and irrigation/power-generation reservoirs. The influence of stocking on abundance and condition of channel catfish varied with ecosystem type. In sand pits, stocking negatively influenced fish condition, and only frequent stocking positively influenced abundance. In flood-control reservoirs, stocking did not influence fish condition, but was associated with greater abundance. Stocking did not influence fish condition or abundance in irrigation/power-generation reservoirs. Additionally, there was evidence that mortality and growth rates varied with ecosystem type. In general, populations from irrigation/power-generation reservoirs were predicted to experience slower growth and lower mortality, whereas populations from sand pits were predicted to experience the fastest growth and highest mortality. Catch rates of channel catfish were substantially less in this study compared to previous records of tandem-set hoop net surveys, but hoop nets were more efficient than the current standard gear, experimental gill nets, at capturing channel catfish (i.e., 100 fish could be captured with fewer hoop net sets than gill net sets). However, catch rates and size structure of channel catfish in tandem-set hoop nets varied within the sampling season and between years. Furthermore, length-frequency distributions of channel catfish were dissimilar between hoop nets and gill nets. Adviser: Kevin L. Pop