425 research outputs found

    Music Synthesizer Senior Project: Danalog

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    The Danalog is a 25 key portable digital music synthesizer that uses multiple synthesis methods and effects to generate sounds. Sound varieties included three synthesis methods including FM, subtractive, and sample-based, with up to eight adjustable parameters, at least four effects, including reverb, chorus, and flange, with five adjustable parameters, and at least two note polyphony, and a five band equalizer. The user would be able to adjust these effects using digital encoders and potentiometers and view the settings on two LCD screens. The finals project was unable to meet the original design requirements. The FM synthesis method was primarily working in the end product. The synthesizer was built to produce two note polyphony. The LCD screens displayed the information about the synthesis method as the user plays

    Analog Single Sideband-Pulse Width Modulation Processor for Parametric Acoustic Arrays

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    Parametric acoustic arrays are ultrasonic-based loudspeakers that produce highly directive audio. The audio must first be preprocessed and modulated into an ultrasonic carrier before being emitted into the air, where it will self-demodulate in the far field. The resulting audio wave is proportional to the double time-derivative of the square of the modulation envelope. This thesis presents a fully analog processor which encodes the audio into two Pulse Width Modulated (PWM) signals in quadrature phase and sums them together to produce a Single Sideband (SSB) spectrum around the fundamental frequency of the PWM signals. The two signals are modulated between 8% and 24% duty cycle to maintain a quasi-linear relationship between the duty cycle and the output signal level. This also allows the signals to sum without overlapping each other, maintaining a two-level output. The system drives a network of narrowband transducers with a center frequency equal to the PWM fundamental. Because the transducers are voltage driven, they have a bandpass frequency response which behaves as a first-order integrator on the SSB signal, eliminating the need for two integrators in the processor. Results show that the “SSB-PWM” output wave has a consistent 20-30dB difference in magnitude between the upper sideband and lower sideband. In simulation, a single tone test shows higher total harmonic distortion for lower frequencies and higher modulation depth. A two-tone test creates a 2nd order intermodulation term that increases with the frequencies of the input signals

    Evaluating the informatics for integrating biology and the bedside system for clinical research

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    pre-printBackground: Selecting patient cohorts is a critical, iterative, and often time-consuming aspect of studies involving human subjects; informatics tools for helping streamline the process have been identified as important infrastructure components for enabling clinical and translational research. We describe the evaluation of a free and open source cohort selection tool from the Informatics for Integrating Biology and the Bedside (i2b2) group: the i2b2 hive. Methods: Our evaluation included the usability and functionality of the i2b2 hive using several real world examples of research data requests received electronically at the University of Utah Health Sciences Center between 2006 - 2008. The hive server component and the visual query tool application were evaluated for their suitability as a cohort selection tool on the basis of the types of data elements requested, as well as the effort required to fulfill each research data request using the i2b2 hive alone. Results: We found the i2b2 hive to be suitable for obtaining estimates of cohort sizes and generating research cohorts based on simple inclusion/exclusion criteria, which consisted of about 44% of the clinical research data requests sampled at our institution. Data requests that relied on post-coordinated clinical concepts, aggregate values of clinical findings, or temporal conditions in their inclusion/exclusion criteria could not be fulfilled using the i2b2 hive alone, and required one or more intermediate data steps in the form of pre-or post-processing, modifications to the hive metadata, etc. Conclusion: The i2b2 hive was found to be a useful cohort-selection tool for fulfilling common types of requests for research data, and especially in the estimation of initial cohort sizes. For another institution that might want to use the i2b2 hive for clinical research, we recommend that the institution would need to have structured, coded clinical data and metadata available that can be transformed to fit the logical data models of the i2b2 hive, strategies for extracting relevant clinical data from source systems, and the ability to perform substantial pre- and post-processing of these data

    Impacts of drought and herbicide stress on seed germination and early seedling growth in a legume crop mung bean (Vigna radiata L.)

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    Abiotic stress such as drought and agrochemicals leads the drastic reductions in legume yields, hence, in order to mitigate the loss of yields due to abiotic stresses, the production of stress tolerance genotypes of the legumes could be a rewarding approach. Therefore, the aim of the present study was to evaluate the drought and herbicide stress effects under ex-vitro conditions on seed germination and early seedling growth in a legume crop mung bean (Vigna radiata L.). To begin with, drought stress was induced by employing various concentrations of mannitol (50mM, 100mM, 250mM, 500mM, 750mM, and 1000mM) and polyethylene glycol (PEG-5%, 10%, 15%, 20%, and 25%) while during herbicide stress experiments, dicamba (3,6-dichloro-2-methoxybenzoic acid) and picloram (4-Amino-3,5,6-trichloro-2-pyridine carboxylic acid) were considered in various concentrations (5mg/L, 25mg/L, 50mg/L, and 100mg/L) of each. Moreover, data were collected as partial and full seed germination after 3- and 7-days of stress treatments respectively. After 7-days of mannitol stress treatments, results reveals that even the high concentration of mannitol (500mM) could be proved as weak osmotic stressor for seed germination (35%±0.14) in comparison to control (91%±0.74) while further increase in mannitol concentration (750mM) was proved to be lethal, toxic and inhibits seed germination completely. Furthermore, in comparison to mannitol, PEG turns out as strong osmotic stressors and (15%) of PEG was proved to very lethal for seed germination. Even during early seedling growth, increased concentrations of both mannitol and PEG were found to be inhibitory. Among two herbicides, the result shows that both herbicides (dicamba and picloram) were proved to be completely toxic and lethal even at very low concentrations (5mg/L) and induced abnormal seed germination and inhibited completely seedling growth. However, the inhibitory response of picloram herbicide stress on seed germination was found to be more pronounced and severe than dicamba herbicide. Hence, the present study reveals that in comparison to mannitol, PEG turns out as a strong osmotic stressor while picloram proves to be a relatively more toxic herbicide than dicamba for seed germination. Additionally, drought stress induced seedlings on transfer to soil exhibit inhibited growth under continuous irrigation with either mannitol or PEG solutions.

    Integrating historical clinical and financial data for pharmacological research

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    pre-printBackground: Retrospective research requires longitudinal data, and repositories derived from electronic health records (EHR) can be sources of such data. With Health Information Technology for Economic and Clinical Health (HITECH) Act meaningful use provisions, many institutions are expected to adopt EHRs, but may be left with large amounts of financial and historical clinical data, which can differ significantly from data obtained from newer systems, due to lack or inconsistent use of controlled medical terminologies (CMT) in older systems. We examined different approaches for semantic enrichment of financial data with CMT, and integration of clinical data from disparate historical and current sources for research. Methods: Snapshots of financial data from 1999, 2004 and 2009 were mapped automatically to the current inpatient pharmacy catalog, and enriched with RxNorm. Administrative metadata from financial and dispensing systems, RxNorm and two commercial pharmacy vocabularies were used to integrate data from current and historical inpatient pharmacy modules, and the outpatient EHR. Data integration approaches were compared using percentages of automated matches, and effects on cohort size of a retrospective study. Results: During 1999-2009, 71.52%-90.08% of items in use from the financial catalog were enriched using RxNorm; 64.95%-70.37% of items in use from the historical inpatient system were integrated using RxNorm, 85.96%-91.67% using a commercial vocabulary, 87.19%-94.23% using financial metadata, and 77.20%-94.68% using dispensing metadata. During 1999-2009, 48.01%-30.72% of items in use from the outpatient catalog were integrated using RxNorm, and 79.27%-48.60% using a commercial vocabulary. In a cohort of 16304 inpatients obtained from clinical systems, 4172 (25.58%) were found exclusively through integration of historical clinical data, while 15978 (98%) could be identified using semantically enriched financial data. Conclusions: Data integration using metadata from financial/dispensing systems and pharmacy vocabularies were comparable. Given the current state of EHR adoption, semantic enrichment of financial data and integration of historical clinical data would allow the repurposing of these data for research. With the push for HITECH meaningful use, institutions that are transitioning to newer EHRs will be able to use their older financial and clinical data for research using these methods

    Stability of nonlinear one-dimensional laser pulse solitons in a plasma

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    In a recent one-dimensional numerical fluid simulation study [Saxena et al., Phys. Plasmas 13,032309 (2006)], it was found that an instability is associated with a special class of one-dimensional nonlinear solutions for modulated light pulses coupled to electron plasma waves in a relativistic cold plasma model. It is shown here that the instability can be understood on the basis of the stimulated Raman scattering phenomenon and the occurrence of density bursts in the trailing edge of the modulated structures are a manifestation of an explosive instability arising from a nonlinear phase mixing mechanism.Comment: 17 pages, 7 figures, Published in Phys. Plasma

    Smart Airport App

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    We are going to make an app that can be used by people traveling through or from ORD airport (Chicago), which will provide live time update for security check line (in terms of time), change of gate for the flight and whether or not the flight is on time. The reason for developing this application is to simplify and improve the passenger’s overall airport experience in order to make it more enjoyable, informative, and time efficient while decreasing the current negative mentality towards traveling. Resources needed to create the prototype would include softwares that help in creating wireframes of the applications like Balsamiq and app developing softwares like Android studio and Xcode. The anticipated beneficiaries of this project would be the consumers that are being provided a smoother airport experience, as well as the airport operators who will be able to provide a better service to the customers with the data collected. An expected result of this app is that fewer passengers will miss their flights; by focusing on waiting times, flight schedules, flight locations, and other airport operations, it can be assumed that users of this app will have more control in the travel process and therefore will make educated decisions based on real time data to make their flight on time. The constraints for this app will be that it is only available on Android-OS compatible phones. Only O’Hare International Airport in Chicago, Illinois will be functional at the time of app release while the team learns about the learning capabilities of the ap

    Sub-grid drag model for immersed vertical cylinders in fluidized beds

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    Immersed vertical cylinders are often used as heat exchangers in gas-solid fluidized beds. CFD simulations are computationally expensive for large scale systems with bundles of cylinders. Therefore sub-grid models are required to facilitate simulations on a coarser grid, where internal cylinders are treated as a porous medium. The influences of cylinders on the gas-solid flow tend to enhance segregation and affect the gas-solid drag. A correction of gas-solid drag must be modeled via suitable sub-grid constitutive relationship. In the past, Sarkar et al. 2013 (1) have developed a sub-grid drag model for horizontal cylinder arrays based on 2D simulations. However, the effect of vertical cylinder arrangement was not considered due to computational complexities. In this work, highly resolved 3D simulations with vertical cylinders were performed in a periodic domain with imposed pressure drop. These simulations were filtered to construct a sub-grid drag model, which can be implemented in coarse-grid simulations. Gas-solid drag was filtered for different average solids fractions; instantaneous snap shots for various average solid fractions are shown in Fig. 1. A reduction in drag was identified as shown in Fig. 2 (a), when compared with simulation without cylinders, and with horizontal cylinders. Fig 2 (b) shows that slip velocities significantly increases when vertical cylinders are present. Vertical suspension drag due to vertical cylinders is insignificant, but substantial horizontal suspension drag is observed. REFERENCE 1.A. Sarkar, X. Sun and S. Sundaresan. Sub-grid drag models for horizontal cylinder arrays immersed in gas-particle multiphase flows. Chem. Eng. Sci.104399–412, 2013. Please click Additional Files below to see the full abstract

    Secure E-mailing System Using Pair Based Scheme and AES with Session Password

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    In early days Textual passwords are used for security of session but these passwords are vulnerable to the various attacks like Dictionary attack, Shoulder surfing, eves dropping, etc. Further graphical passwords and bio-metric passwords are invented. These two techniques are good performer but they have their own disadvantages. Such as requires extra time for login and more cost respectively. Thus we proposed a session password scheme in which the passwords are used only once for each and when session is terminated the password is no longer in use. The proposed of session password scheme uses Pair Based Authentication scheme for generating session password. In every Data communication system security to data is primary aim. Data security can be provided by many ways. This Paper gives a design of effective security for data communication in network by AES algorithm for encryption and decryption
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