Fixed gain and adaptive techniques for rotorcraft vibration control

The results of an analysis effort performed to demonstrate the feasibility of employing approximate dynamical models and frequency shaped cost functional control law desgin techniques for helicopter vibration suppression are presented. Both fixed gain and adaptive control designs based on linear second order dynamical models were implemented in a detailed Rotor Systems Research Aircraft (RSRA) simulation to validate these active vibration suppression control laws. Approximate models of fuselage flexibility were included in the RSRA simulation in order to more accurately characterize the structural dynamics. The results for both the fixed gain and adaptive approaches are promising and provide a foundation for pursuing further validation in more extensive simulation studies and in wind tunnel and/or flight tests

CO and HCN isotopologue ratios in the outflows of AGB stars

Isotopologue line intensity ratios of circumstellar molecules have been widely used to trace the photospheric elemental isotopic ratios of evolved stars. However, depending on the molecular species and the physical conditions of the environment, the circumstellar isotopologue ratio may deviate considerably from the stellar atmospheric value. In this paper, we aim to examine how the CO and HCN abundance ratios vary radially due to chemical reactions in the outflows of AGB stars and the effect of excitation and optical depth on the resulting line intensity ratios. We find that the circumstellar 12CO/13CO can deviate from its atmospheric value by up to 25-94% and 6-60% for C- and O-type CSEs, respectively. We show that variations of the intensity of the ISRF and the gas kinetic temperature can significantly influence the CO isotopologue ratio in the outer CSEs. On the contrary, the H12CN/H13CN ratio is stable for all tested mass-loss rates. The RT modeling shows that the integrated line intensity ratio of CO of different rotational transitions varies significantly for stars with intermediate mass-loss rates due to combined chemical and excitation effects. In contrast, the excitation conditions for the both HCN isotopologues are the same. We demonstrate the importance of using the isotopologue abundance profiles from chemical models as inputs to RT models in the interpretation of isotopologue observations. Previous studies of CO isotopologue ratios are based on multi-transition data for individual sources and it is difficult to estimate the errors in the reported values due to assumptions that are not entirely correct according to this study. If anything, previous studies may have overestimated the circumstellar 12CO/13CO abundance ratio. The use of the HCN as a tracer of C isotope ratios is affected by fewer complicating problems, provided one accounts corrections for high optical depths.Comment: 14 pages, 11 figure

VARIwise: a general-purpose adaptive control simulation framework for spatially and temporally varied irrigation at sub-field scale

Irrigation control strategies may be used to improve the site-specific irrigation of cotton via lateral move and centre pivot irrigation machines. A simulation framework ‘VARIwise’ has been created to aid the development, evaluation and management of spatially and temporally varied site-specific irrigation control strategies. VARIwise accommodates sub-field scale variations in all input parameters using a 1 m2 cell size, and permits application of differing control strategies within the field, as well as differing irrigation amounts down to this scale. In this paper the motivation and objectives for the creation of VARIwise are discussed, the structure of the software is outlined and an example of the use and utility of VARIwise is presented. Three irrigation control strategies have been simulated in VARIwise using a cotton model with a range of input parameters including spatially variable soil properties, non-uniform irrigation application, three weather profiles and two crop varieties. The simulated yield and water use efficiency were affected by the combination of input parameters and the control strategy implemented

Model-Agnostic Syntactical Information for Pre-Trained Programming Language Models

Pre-trained Programming Language Models (PPLMs) achieved many recent states of the art results for many code-related software engineering tasks. Though some studies use data flow or propose tree-based models that utilize Abstract Syntax Tree (AST), most PPLMs do not fully utilize the rich syntactical information in source code. Still, the input is considered a sequence of tokens. There are two issues; the first is computational inefficiency due to the quadratic relationship between input length and attention complexity. Second, any syntactical information, when needed as an extra input to the current PPLMs, requires the model to be pre-trained from scratch, wasting all the computational resources already used for pre-training the current models. In this work, we propose Named Entity Recognition (NER) adapters, lightweight modules that can be inserted into Transformer blocks to learn type information extracted from the AST. These adapters can be used with current PPLMs such as CodeBERT, GraphCodeBERT, and CodeT5. We train the NER adapters using a novel Token Type Classification objective function (TTC). We insert our proposed work in CodeBERT, building CodeBERTER, and evaluate the performance on two tasks of code refinement and code summarization. CodeBERTER improves the accuracy of code refinement from 16.4 to 17.8 while using 20% of training parameter budget compared to the fully fine-tuning approach, and the BLEU score of code summarization from 14.75 to 15.90 while reducing 77% of training parameters compared to the fully fine-tuning approach.Comment: 11 pages, 5 Figures, Has been accepted on ICSE 202

Ancilla-assisted sequential approximation of nonlocal unitary operations

We consider the recently proposed "no-go" theorem of Lamata et al [Phys. Rev. Lett. 101, 180506 (2008)] on the impossibility of sequential implementation of global unitary operations with the aid of an itinerant ancillary system and view the claim within the language of Kraus representation. By virtue of an extremely useful tool for analyzing entanglement properties of quantum operations, namely, operator-Schmidt decomposition, we provide alternative proof to the "no-go" theorem and also study the role of initial correlations between the qubits and ancilla in sequential preparation of unitary entanglers. Despite the negative response from the "no-go" theorem, we demonstrate explicitly how the matrix-product operator(MPO) formalism provides a flexible structure to develop protocols for sequential implementation of such entanglers with an optimal fidelity. The proposed numerical technique, that we call variational matrix-product operator (VMPO), offers a computationally efficient tool for characterizing the "globalness" and entangling capabilities of nonlocal unitary operations.Comment: Slightly improved version as published in Phys. Rev.

Relationship of Anemia and Serum Ferritin in Medical Students

Aims: Anemia occurs for different reasons. However the Iron Deficiency Anemia (IDA) is one of the most prevalent causes of anemia in all human communities. The goal of the present study was to assess the effect of serum Ferritin deficiency on anemia in medical students. Materials & Methods: This cross-sectional study was conducted on students of Kashan University of Medical Sciences in all educational stages in 2011. 323 students were selected randomly. The hemoglobin, hematocrit, MCV, MCH, MCHC, ferritin and RDW indices were measured. The data was analyzed by SPSS 13 statistical software using Chi-square and independent T tests. Findings: The mean of ferritin level in all samples was 46.2±42.8ng/ml, hemoglobin was 13.1±1.4g/dl, hematocrit was 39.2±5.2, MCV was 85.4±6.4fl, MCH was 29.2±6.1, MCHC was 32.9±1.3g/dl and RDW was 13.6±0.5g/dl. 62 of studied individuals (19.2) had minor anemia and 261 (80.8) were normal. 31 of studied individuals (9.6) had ferritin deficiency and 292 (90.4) had normal ferritin. There was a significant difference between anemia according to gender (p=0.001) and educational level (p=0.01). Ferritin deficiency had also significant difference according to gender. According to gender, there were significant differences in ferritin, hemoglobin, hematocrit and RDW levels. According to age, there were significant differences between ferritin and hematocrit and RDW levels. MCHC level had significant difference according to living site of the students. Conclusion: Girl university students are at the risk of anemia caused by lack of ferritin and aging increases the risk of anemia