1,190 research outputs found
On-line temperature estimation of SiC power MOSFET modules through on-state resistance mapping
The paper deals with real-time estimation of the junction temperature of a SiC power MOSFET modules. The junction temperature of one device of the module is real-time estimated by measuring its current and on-state voltage at each time sample, and entering the temperature model of the device. The temperature model is obtained in a dedicated commissioning session, where the vON is measured at different temperature and current conditions. A sequence of current pulses of short duration is closed-loop imposed to the device at different values of the measured DBC substrate temperature, so that the temperature measurement is consistently representing the junction temperature during the identification. The presented results show that the proposed method permits on-line temperature monitoring and even closed loop regulation of the junction temperature of the tested SiC power MOSFET modules. Different module from two different manufacturers are tested under realistic operating conditions. This concept can be usefully applied to all DC/AC conversion structures, where the monitoring of one device can be of reference value for the entire module
Toward Black-Box Detection of Logic Flaws in Web Applications
Abstract—Web applications play a very important role in many critical areas, including online banking, health care, and personal communication. This, combined with the limited security training of many web developers, makes web applications one of the most common targets for attackers. In the past, researchers have proposed a large number of white- and black-box techniques to test web applications for the presence of several classes of vulnerabilities. However, traditional approaches focus mostly on the detection of input validation flaws, such as SQL injection and cross-site scripting. Unfortunately, logic vulnerabilities specific to particular applications remain outside the scope of most of the existing tools and still need to be discovered by manual inspection. In this paper we propose a novel black-box technique to detect logic vulnerabilities in web applications. Our approach is based on the automatic identification of a number of behavioral patterns starting from few network traces in which users interact with a certain application. Based on the extracted model, we then generate targeted test cases following a number of common attack scenarios. We applied our prototype to seven real world E-commerce web applications, discovering ten very severe and previously-unknown logic vulnerabilities. I
Exposure to the natural alkaloid Berberine affects cardiovascular system morphogenesis and functionality during zebrafish development
The plant-derived natural alkaloid berberine displays therapeutic potential to treat several pathological conditions, including dyslipidemias, diabetes and cardiovascular disorders. However, data on berberine effects during embryonic development are scarce and in part controversial. In this study, using zebrafish embryos as vertebrate experimental model, we address the effects of berberine treatment on cardiovascular system development and functionality. Starting from the observation that berberine induces developmental toxicity and pericardial edema in a time- and concentration-dependent manner, we found that treated embryos display cardiac looping defects and, at later stages, present an abnormal heart characterized by a stretched morphology and atrial endocardial/myocardial detachment. Furthermore, berberine affected cardiac functionality of the embryos, promoting bradycardia and reducing the cardiac output, the atrial shortening fraction percentage and the atrial stroke volume. We also found that, during development, berberine interferes with the angiogenic process, without altering vascular permeability. These alterations are associated with increased levels of vascular endothelial growth factor aa (vegfaa) mRNA, suggesting an important role for Vegfaa as mediator of berberine-induced cardiovascular defects. Altogether, these data indicate that berberine treatment during vertebrate development leads to an impairment of cardiovascular system morphogenesis and functionality, suggesting a note of caution in its use during pregnancy and lactation
Anterolateral Ligament of the Knee: Back to the Future in Anterior Cruciate Ligament Reconstruction
Although the importance of the anterolateral stabilizing structures of the knee in the setting of anterior cruciate ligament (ACL) injuries has been recognized since many years, most of orthopedic surgeons do not take into consideration the anterolateral structures when performing an ACL reconstruction. Anatomic single or double bundle ACL reconstruction will improve knee stability, but a small subset of patients may experience some residual anteroposterior and rotational instability. For this reason, some researchers have turned again towards the anterolateral aspect of the knee and specifically the anterolateral ligament. The goal of this review is to summarize the existing knowledge regarding the anterolateral ligament of the knee, including anatomy, histology, biomechanics and imaging. In addition, the most common anterolateral reconstruction/tenodesis techniques are described together with their respective clinical outcomes
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