Towards efficient decoding of classical-quantum polar codes

Known strategies for sending bits at the capacity rate over a general channel with classical input and quantum output (a cq channel) require the decoder to implement impractically complicated collective measurements. Here, we show that a fully collective strategy is not necessary in order to recover all of the information bits. In fact, when coding for a large number N uses of a cq channel W, N I(W_acc) of the bits can be recovered by a non-collective strategy which amounts to coherent quantum processing of the results of product measurements, where I(W_acc) is the accessible information of the channel W. In order to decode the other N (I(W) - I(W_acc)) bits, where I(W) is the Holevo rate, our conclusion is that the receiver should employ collective measurements. We also present two other results: 1) collective Fuchs-Caves measurements (quantum likelihood ratio measurements) can be used at the receiver to achieve the Holevo rate and 2) we give an explicit form of the Helstrom measurements used in small-size polar codes. The main approach used to demonstrate these results is a quantum extension of Arikan's polar codes.Comment: 21 pages, 2 figures, submission to the 8th Conference on the Theory of Quantum Computation, Communication, and Cryptograph

Cover Crops and Cover Crop Mixes: Stratification of Biological Effects

The potential nutrient cycling benefits from legumes (e.g. N2-fixation) and the high biomass potential of cereal rye are well known. Further studies are warranted to evaluate bi-culture mixtures and their effects on soil nutrient stratification and microbial enzyme activity because these two properties may be differently expressed (enhanced) by legume/grass mixes. The objectives of this study were: (1) show different cover crops and cover crop mixes containing grasses and legumes differentially stratify carbon and N; (2) show the change in microbial enzyme activity in soils planted with individual cover crops relative to cover crop mixes; 3) determine the persistence of any changes after a summer annual crop. Baseline samples were collected in fall 2016 at 0-15 and 15-30 cm depths after a seasonal fallow and a summer maize crop. Cover crop mixes were planted in fall 2016, terminated in spring 2017, and a summer hemp crop (Cannabis sativa) planted. After cover crop termination and hemp harvest, soils were sampled at 0-7.5, 7.5-15, and 15-30 cm depths. Total C, total N, total P, mineralizable N, POXc (labile C), and four soil enzymes (phosphatase, sulfatase, glucosidase, and urease) were evaluated. Stratification ratios decreased following cover crops. Cover crop mixes stratified mineralizable N deeper than legumes alone in five of six instances. Enzyme activity increased following cover crops, but there was little significance due to cover crop type. Cover crop mixtures did not significantly increase measured variables more than single species did. This study did not demonstrate an advantage to using either an individual grass or legume or mixture in terms of enhancing soil quality parameters

Business Intelligence Tools in a Developmental Environment: An Academic Module

Business Intelligence (BI), defined here as the creation and use of meaningful business information for management, has over the last 20 years shown over and over again its value to professional industry. The prevalence of BI has also demonstrated that a new brand of worker is needed to take advantage of the sophisticated tools available to modern industry. Evidence suggests modern universities have struggled to educate professionals on the tremendous impact BI can have on an organization if used properly. This work is a step in an endeavor to bridge that educational gap and generate an educational strategic advantage by providing a module to be used in current information systems courses

I Would Teach It If I Knew How: Inquiry, Modeling, Shared Writing, Collaborative Writing, and Independent Writing (IMSCI), a Model for Increasing Secondary Teacher Self-Efficacy in Integrating Writing Instruction in the Content Areas

Framed in theories of pragmatism, self-efficacy, and ecology, this design-based research study attempted to make explicit connections between theory and field-based research. The pedagogical goal of this study was to expose in-service teachers to a scaffolded model of professional development for writing (IMSCI) that could be implemented in their own teaching. This model of professional development also served to place research participants in a professional learning community. Teachers worked in focus groups made of another teacher in their own discipline, and a collective focus group, and worked through the steps of the scaffolded model in consideration of their own writing instruction in an effort to increase their self-efficacy, while also experiencing a participatory approach to instruction that in turn improved their ability to enact this instruction in their own classrooms. The data, which included focus group interviews, blog posts by the teachers, and member checking, were analyzed using constant comparative methods. The analyses indicated that the majority of these content teachers had not experienced effective writing instruction models as students and did not learn how to teach writing in their preservice teaching programs. Additionally, their professional learning experiences as inservice teachers had not given them the tools they needed to overcome ecological factors that stopped them from teaching writing. Teachers\u27 responses about their experience with the IMSCI model indicate that it has the potential to help teachers understand what effective writing instruction looks like, how to implement it in their own classrooms, and to increase their perceived self-efficacy as teachers of writing

MIMO transmission equation

Journal ArticleMultiple-input, multiple-output (MIMO) antenna systems such as the one depicted in Fig. 1 offer capacity benefits over their single-input, single-output (SISO) counterparts [1], thus attracting considerable current research. MIMO performance depends on a wide range of parameters [1] including radiation efficiency, correlation [2], mutual coupling [3], matching efficiency and polarization misalignment [4]. No single simulation method has been described that includes each of these effects so critical to handset array designs. This work synthesizes a comprehensive model to incorporate each of these effects. In order to manage the complexity of such a model, the MIMO Transmission Equation is introduced-similar to the well-known Friis Transmission Equation

Decoherence suppression via environment preparation

To protect a quantum system from decoherence due to interaction with its environment, we investigate the existence of initial states of the environment allowing for decoherence-free evolution of the system. For models in which a two-state system interacts with a dynamical environment, we prove that such states exist if and only if the interaction and self-evolution Hamiltonians share an eigenstate. If decoherence by state preparation is not possible, we show that initial states minimizing decoherence result from a delicate compromise between the environment and interaction dynamics.Comment: 4 pages, 2 figure

Letter to C.P. McIlvaine

Strong Letterbook no. 87, request to give sermonhttps://digital.kenyon.edu/mcilvaine_letters/1257/thumbnail.jp

Statistical comparison of capacity predictions for realistic MIMO channels

Journal ArticleThe impact of antenna polarization on channel capacity is explored in multiple-input, multiple-output (MIMO) systems. An idealized polarization model involving branch power rations (BPR's) and channel cross-coupling is incorporated into channel-specific capacity calculations. Results are compared for several measured channels including line-of-sight (LOS) and non-line-of-sight (NLOS) both indoors and outdoors yielding valuable sensitivity analyses for channel capacity. Virtually all channels achieve perchannel peak capacities of 50% above that of single-input, single-output (SISO) channels and are well suited to opportunistic scheduling. However, systems exclusively dependent on polarization diversity will often exhibit outage capacities of just 10% above SISO capacity and will perform worse than those dependent on additional degrees of freedom