5 research outputs found

    Secure and Efficient Video Transmission in VANET

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    Currently, vehicular communications have become a reality used by various applications, especially applications that broadcast video in real time. However, the video quality received is penalized by the poor characteristics of the transmission channel (availability, non-stationarity, the ration of signal-to-noise, etc.). To improve and ensure minimum video quality at reception, we propose in this work a mechanism entitled “Secure and Efficient Transmission of Videos in VANET (SETV)”. It's based on the "Quality of Experience (QoE)" and using hierarchical packet management. This last is based on the importance of the images of the stream video. To this end, the use of transmission error correction with uneven error protection has proven to be effective in delivering high quality videos with low network overhead. This is done based on the specific details of video encoding and actual network conditions such as signal to noise ratio, network density, vehicle position and current packet loss rate (PLR) not to mention the prediction of the future DPP.Machine learning models were developed on our work to estimate perceived audio-visual quality. The protocol previously gathers information about its neighbouring vehicles to perform distributed jump reinforcement learning. The simulation results obtained for several types of realistic vehicular scenarios show that our proposed mechanism offers significant improvements in terms of video quality on reception and end-to-end delay compared to conventional schemes. The results prove that the proposed mechanism has showed 11% to 18% improvement in video quality and 9% load gain compared to ShieldHEVC

    Pulmonary Barotrauma Including Huge Pulmonary Interstitial Emphysema in an Adult with Status Asthmaticus: Diagnostic and Therapeutic Challenges

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    Introduction: Pulmonary interstitial emphysema is a rare finding defined as abnormal air collection inside the lung interstitial tissues. Described more frequently in ventilated new-borns, pulmonary interstitial emphysema is an uncommon barotrauma-related complication in adults. Management and clinical sequelae are poorly described. Patient: We describe the case of a 64-year-old man who presented with huge pulmonary interstitial emphysema together with simultaneous pulmonary barotrauma in status asthmaticus requiring invasive ventilation. Discussion: There are no guidelines for the management of such complications and their possible sequelae but conservative treatment seems to be effective. The treatment of our patient is described

    Metastatic Clear Cell Hidradenocarcinoma: Response to Chemotherapy and Long Disease Control

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    Introduction: Hidradenocarcinoma is a rare aggressive tumor arising from sweat glands that may occur from preexisting hidradenoma or most frequently appears de novo. It is often located in the head and neck. It is also characterized by a high potential of local recurrence, metastasis and poor outcome. This tumor is often radiotherapy and chemotherapy resistant.Presentation of case: We report a case of a 77-year-old man with a metastatic hidradenocarcinoma to the bone and lymph nodes who was operated 7 years ago for an hidradenoma of the right foot. He was treated with capecitabine-based chemotherapy with good tolerance and obtention of partial response during 10 months. After that, his disease progressed and he died 1 year after diagnosis.Conclusion: Hidradenocarcinoma is a cancer with a poor prognosis . Because of its low prevalence and high rate of recurrence, its treatment is still controversial. Our good result demonstrates that adjunction of chemotherapy in metastatic forms is effective for a better control and long overall survival

    A Novel Approach Based on Crow Search Algorithm for Solving Reactive Power Dispatch Problem

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    This paper presents a novel meta-heuristic approach based on the crow search algorithm (CSA) for solving the optimal reactive power dispatch (ORPD) problem. The ORPD is formulated as a nonlinear optimization problem designed to minimize power losses while satisfying the required constraints. The CSA is a recent efficient approach that depends on the intelligent behavior of crows. Nowadays, it has been used to solve many complex engineering optimization problems where it has proven its power and effectiveness. Motivated by the high ability in solving complex optimization problems and faster convergence of CSA, this paper proposes a novel approach to solve the ORPD problem. Furthermore, the settings of control variables such as generator terminal voltage, tap changer positions, and capacitor banks are determined to achieve the minimum total power loss while satisfying a set of nonlinear constraints. The accuracy and the performance of the proposed algorithm were performed and compared to other meta-heuristic algorithms reported in the literature. Several tests are applied on two standard test systems, including IEEE 14-bus and IEEE 30-bus as well as on the large-scale Tunisian 86-bus system. In addition, a sensitivity analysis has been performed to valid the performance of the CSA in solving the ORPD problem. We demonstrate that the proposed CSA provides a supremacy results and statistically significant in solving ORPD problems (for IEEE-14 bus p < 0.0006 , for IEEE-30 bus p < 0.006 , and for Tunisian 86-bus p < 0.0000001 )

    Granulosa Cell Tumor of the Ovary: A Retrospective Study of 31 Cases and a Review of the Literature

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    Background. Adult granulosa cell tumors (AGCTs) are the most common sex cord-stromal tumors. Unlike epithelial ovarian tumors, they occur in young women and are usually detected at an early stage. The aim of this study was to report the clinical and pathological characteristics of AGCT patients and to identify the prognostic factors. Methods. All cases of AGCTs, treated at Salah Azaïz Institute between 1995 and 2010, were retrospectively included. Kaplan-Meier’s statistical method was used to assess the relapse-free survival and the overall survival. Results. The final cohort included 31 patients with AGCT. The mean age was 53 years (35–73 years). Patients mainly presented with abdominal mass and/or pain (61%, n=19). Mean tumor size was 20 cm. The majority of patients had a stage I disease (61%,  n=19). Two among 3 patients with stage IV disease had liver metastasis. Mitotic index was low in 45% of cases (n=14). Surgical treatment was optimal in almost all cases (90%, n=28). The median follow-up time was 14 years (1–184 months). Ten patients relapsed (32%) with a median RFS of 8.4 years (6.8–9.9 years). Mean overall survival was 13 years (11–15 years). Stage I disease and low-to-intermediate mitotic index were associated with a better prognosis in univariate analysis (resp., p=0.05 and p=0.02) but were not independent prognostic factors. Conclusion. GCTs have a long natural history with common late relapses. Hence, long active follow-up is recommended. In Tunisian patients, hepatic metastases were more frequent than occidental series. The prognosis remains good and initial staging at diagnosis is an important prognostic factor
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