1,492 research outputs found

    PALS/PRISM Software Design Description (SDD): Ver. 0.51

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    This Software Design Description (SDD) provides detailed information on the architecture and coding for the PRISM C++ library (version 0.51). The PRISM C++ library supports consistent information sharing and in- teractions between distributed components of networked embedded systems, e.g. avionics. It is designed to reduce the complexity of the networked sys- tem by employing synchronous semantics provided by the architectural pat- tern called a Physically-Asynchronous Logically-Synchronous (PALS) system.unpublishednot peer reviewe

    Low complexity system architecture design for medical Cyber-Physical-Human Systems (CPHS)

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    Cyber-Physical-Human Systems (CHPS) are safety-critical systems, where the interaction between cyber components and physical components can be influenced by the human operator. Guaranteeing correctness and safety in these highly interactive computations is challenging. In particular, the interaction between these three components needs to be coordinated collectively in order to conduct safe and effective operations. The interaction nevertheless increases by orders of magnitude the levels of complexity and prevents formal verification techniques, such as model checking, from thoroughly verifying the safety and correctness properties of systems. In addition, the interactions could also significantly increase human operators' cognitive load and lead to human errors. In this thesis, we focus on medical CPHS and examine the complexity from a safety angle. Medical CPHS are both safety-critical and highly complex, because medical staff need to coordinate with distributed medical devices and supervisory controllers to monitor and control multiple aspects of the patient's physiology. Our goal is to reduce and control the complexity by introducing novel architectural patterns, coordination protocols and user-centric guidance system. This thesis makes three major contributions for improving safety of medical CPHS. Reducing verification complexity: Formal verification is a promising technique to guarantee correctness and safety, but the high complexity significantly increases the verification cost, which is known as state space explosion problems. We propose two architectural patterns: Interruptible Remote Procedure Call (RPC) and Consistent View Generation and Coordination (CVGC) protocol to properly handle asynchronous communication and exceptions with low complexity. Reducing cyber-medical treatment complexity: Cyber medical treatment complexity is defined as the number of steps and time to perform a treatment and monitor the corresponding physiological responses. We propose treatment and workflow adaptation and validation protocols to semi-autonomously validate the preconditions and adapt the workflows to patient conditions, which reduces the complexity of performing treatments and following best practice workflows. Reducing human cognitive load complexity: Cognitive load (also called mental workload) complexity measures human memory and mental computation demand for performing tasks. We first model individual medical staff's responsibility and team interactions in cardiac arrest resuscitation and decomposed their overall task into a set of distinct cognitive tasks that must be specifically supported to achieve successful human-centered system design. We then prototype a medical Best Practice Guidance (BPG) system to reduce medical staff's cognitive load and foster adherence to best practice workflows. Our BPG system transforms the implementation of best practice medical workflow

    In Situ Confocal Raman Mapping Study of a Single Ti-Assisted ZnO Nanowire

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    In this work, we succeeded in preparing in-plane zinc oxide nanowires using a Ti-grid assisted by the chemical vapor deposition method. Optical spatial mapping of the Confocal Raman spectra was used to investigate the phonon and geometric properties of a single ZnO nanowire. The local optical results reveal a red shift in the non-polar E2 high frequency mode and width broadening along the growth direction, reflecting quantum-confinement in the radial direction

    Langerhans cell hyperplasia in the tumor stage of mycosis fungoides: a mimic of Langerhans cell histiocytosis

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    AbstractMycosis fungoides is a form of cutaneous T-cell lymphoma (CTCL). Malignant CD4+ T cells have been found to adopt the T-regulatory (Treg) cell phenotype and function. We present the case of a 66-year-old man diagnosed with mycosis fungoides that was progressing from the plaque to the tumor stage. The histopathological examinations showed that the Langerhans cell (LC) infiltration in the skin lesion of the tumor stage was greater than that in the patch/plaque stage; the tumor stage lesions resembled LC histiocytosis pathologically. The associations among LCs, apoptotic tumor cells, Treg CTCL cells, and relevant cytokines are complex. Treg CTCL cells produce the immunosuppressive cytokines interleukin-10 and transforming growth factor beta, which facilitate continuous recruitment of LCs and maintenance of long-term dendritic cell immaturity, thereby explaining the remarkable LC infiltration in the tumor stage samples from our patient. This phenomenon indicates that LCs accompanied by Treg CTCL cells may play an important synergistic role in the tumor progression. The development of immunotherapy directed against Treg CTCL cells and LCs overproduction and other immunosuppressive cytokines may be a potent useful adjuvant and worthy of further investigation

    Intermediate layer free PVDF evolved CMS on ceramic hollow fiber membrane for CO2 capture

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    The use of carbonized polymers has ushered in a new class of materials with profound implications for the gas separation industry. This study explored the transformation of polyvinylidene fluoride (PVDF) into microporous carbon structures coated onto ceramic substrates, enabling in situ growth of carbon molecular sieve (CMS) materials over hollow fibers. This material featured more robust CMS membranes than alumina and demonstrated exceptional capability in vital gas separations, particularly for CO2/CH4. This novel approach increased the selectivity for gases and exhibited remarkable aging resilience, so the material is a compelling candidate for high-performance gas separations. Furthermore, after 31 days, the weathered carbon dioxide membrane exhibited a slight permeability drift from 234.88 barrers to 195.35 barrers, while the CO2/CH4 ratio increased from 24.21 to 57.14, surpassing the Robeson 2008 upper bound. The PVDF-derived supported hollow fiber carbon membranes provide a blueprint for designing membranes for carbon capture. With the high packing density of the hollow fiber membrane and improved mechanical strength of the supported carbon membrane, this approach overcame the high fabrication costs and brittleness of other carbon membranes. In addition, the entire process for preparation of the PVDF carbon films is easily scaled up and has great potential for future practical application

    Fabrication of Wireless Micro Pressure Sensor Using the CMOS Process

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    In this study, we fabricated a wireless micro FET (field effect transistor) pressure sensor based on the commercial CMOS (complementary metal oxide semiconductor) process and a post-process. The wireless micro pressure sensor is composed of a FET pressure sensor, an oscillator, an amplifier and an antenna. The oscillator is adopted to generate an ac signal, and the amplifier is used to amplify the sensing signal of the pressure sensor. The antenna is utilized to transmit the output voltage of the pressure sensor to a receiver. The pressure sensor is constructed by 16 sensing cells in parallel. Each sensing cell contains an MOS (metal oxide semiconductor) and a suspended membrane, which the gate of the MOS is the suspended membrane. The post-process employs etchants to etch the sacrificial layers in the pressure sensor for releasing the suspended membranes, and a LPCVD (low pressure chemical vapor deposition) parylene is adopted to seal the etch holes in the pressure. Experimental results show that the pressure sensor has a sensitivity of 0.08 mV/kPa in the pressure range of 0–500 kPa and a wireless transmission distance of 10 cm
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