6,066 research outputs found

    Fault detection and isolation of malicious nodes in MIMO Multi-hop Control Networks

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    A MIMO Multi-hop Control Network (MCN) consists of a MIMO LTI system where the communication between sensors, actuators and computational units is supported by a (wireless) multi-hop communication network, and data flow is performed using scheduling and routing of sensing and actuation data. We provide necessary and sufficient conditions on the plant dynamics and on the communication protocol configuration such that the Fault Detection and Isolation (FDI) problem of failures and malicious attacks to communication nodes can be solved.Comment: 6 page

    Optimal co-design of control, scheduling and routing in multi-hop control networks

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    A Multi-hop Control Network consists of a plant where the communication between sensors, actuators and computational units is supported by a (wireless) multi-hop communication network, and data flow is performed using scheduling and routing of sensing and actuation data. Given a SISO LTI plant, we will address the problem of co-designing a digital controller and the network parameters (scheduling and routing) in order to guarantee stability and maximize a performance metric on the transient response to a step input, with constraints on the control effort, on the output overshoot and on the bandwidth of the communication channel. We show that the above optimization problem is a polynomial optimization problem, which is generally NP-hard. We provide sufficient conditions on the network topology, scheduling and routing such that it is computationally feasible, namely such that it reduces to a convex optimization problem.Comment: 51st IEEE Conference on Decision and Control, 2012. Accepted for publication as regular pape

    Association of endometrioid ovarian carcinoma arising from endometriosis, endometrioid endometrial carcinoma, and high-grade undifferentiated endometrial sarcoma. a case report

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    Endometriosis is a chronic disease that affects women of reproductive age. Malignant transformation in endometriosis is considered to be an unusual event, only occurring in 0.7-0.1% of cases. However the association between endometriosis and endometrial cancer is not well defined. Also in literature, rare cases of uterine sarcoma, about 3% of all uterine malignancies, associated with endometriosis have been reported. The authors report a case of a 47-years-old Italian woman with histologic diagnosis of endometrioid ovarian carcinoma arising from endometriosis, endometrioid endometrial carcinoma, and undifferentiated endometrial sarcoma. Therefore there have been few studies addressing the relationship between endometrial stromal sarcomas (ESS), and endometriosis. Novel scientific findings are necessary to investigate a possible common pathway and an effective treatment, although complete tumor resection can reduce the recurrence rate

    Feedback stabilization of dynamical systems with switched delays

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    We analyze a classification of two main families of controllers that are of interest when the feedback loop is subject to switching propagation delays due to routing via a wireless multi-hop communication network. We show that we can cast this problem as a subclass of classical switching systems, which is a non-trivial generalization of classical LTI systems with timevarying delays. We consider both cases where delay-dependent and delay independent controllers are used, and show that both can be modeled as switching systems with unconstrained switchings. We provide NP-hardness results for the stability verification problem, and propose a general methodology for approximate stability analysis with arbitrary precision. We finally give evidence that non-trivial design problems arise for which new algorithmic methods are needed

    Ovarian endometrioid adenocarcinoma diagnosed in pregnancy. a case report

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    The prevalence of adnexal masses pregnancy is about 0.19-8.8%. The malignancy rate is around 1-6%, and indeed most cases are benign masses. During pregnancy adnexal masses should be accurately evaluated to identify the patients who need surgery from those who need a 'wait-and-see' strategy. The authors report a case of 36-year-old woman (gravida 2, para 2, two vaginal deliveries) referred to the Gynecologic Department with diagnosis of endometrioid ovarian adenocarcinoma. The patient underwent laparotomic surgery with left salpingo-oophorectomy, total hysterectomy, pelvic and para-aortic lymphadenectomy, and peritoneal washing for optimal surgery staging. No ascites or residual tumour in the abdominal cavity were found macroscopically. Histopathology was negative for residual ovarian cancer. Currently the treatment and the management of ovarian cancer are not well established because scientific evidence is limited

    Does postoperative radiation therapy represent a contraindication to expander-implant based immediate breast reconstruction? An update 2012-2014

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    Post-mastectomy radiotherapy (PMRT) is well known in the plastic surgery community for having a negative impact on expander-implant based immediate breast reconstruction (IBBR), although recently some technical improvements allow better results. Very recent papers would suggest that there is no difference in postoperative complications in patients receiving post-mastectomy radiotherapy using modern techniques. However, study results are often biased by small groups of patients and by heterogeneity of radiotherapy timing, different surgical techniques and measured outcomes
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