18 research outputs found
A thermally enhanced bond interface for pixelated LEDs in adaptive front lighting systems
Pixelated LEDs are a new, high efficient light source which allows to control the beam pattern and which are therefore suitable for adaptive front light systems. We will present a concept for hybrid 3D flip chip stacking of pixelated LED chips onto an active matrix driver IC using a new interconnect structure to address thermal management and bonding robustness challenges. Two types of interconnect materials have been investigated: electroplated AuSn solder and nanoporous gold (NPG). We will present the deposition methods and the bonding approach for chip-to-chip and chip-to-wafer bonding and the characteristic results of the bonded interconnects achieved
Security and Privacy in Vehicular Adhoc Networks: a survey and the road ahead
Vehicular Ad-hoc Networks (VANETs) can make roads safer, cleaner, and smarter. It can offer a wide range of services, which can be safety and non-safety related. Many safety-related VANETs applications are real-time and mission critical, which would require strict guarantee of security and reliability. Even non-safety related multimedia applications, which will play an important role in the future, will require security support. Lack of such security and privacy in VANETs is one of the key hindrances to the wide spread implementations of it. An insecure and unreliable VANET can be more dangerous than the system without VANET support. So it is essential to make sure that “life-critical safety” information is secure enough to rely on. Securing the VANETs along with appropriate protection of the privacy drivers or vehicle owners is a very challenging task. In this work we summarize the attacks, corresponding security requirements and challenges in VANETs. We also present the most popular generic security policies which are based on prevention as well detection methods. Many VANETs applications require system-wide security support rather than individual layer from the VANETs’ protocol stack. In this work we will review the existing works in the perspective of holistic approach of security. Finally, we will provide some possible future directions to achieve system-wide security as well as privacy-friendly security in VANETs
On Secure and Privacy-Aware Sybil Attack Detection in Vehicular Communications
The foreseen dream of Vehicular Ad Hoc NETwork (VANET) deployment is obstructed by long-chased security and privacy nightmares. Despite of the increasing demand for perfect privacy, it conflicts with rather more serious security threat called 'Sybil Attack' which refers to, impersonation of one physical entity for many, namely Sybil nodes. In such circumstances, data received from malicious Sybil attacker may seem as if it was received from many distinct physical nodes. Sybil nodes may deliberately mislead other neighbors, resulting in catastrophic situations like traffic jams or even deadly accidents. Preventing such attacks in a privacy-enabled environment is not a trivial task. In this paper, we aim at two conflicting goals, i.e. privacy and Sybil attack in VANET. We leverage pseudonymless beaconing in order to preserve privacy. To cope with Sybil attack, we put forth a twofold strategy. In order to avoid Sybil attack through scheduled beacons, we employ tamper resistant module (TRM) to carry out a pre-assembly data analysis on data that is used to assemble beacons whereas for event reporting message (ERM), we employ road side units (RSUs) to localize Sybil nodes in VANET and report them to the revocation authority(s). RSUs distribute authorized tokens among the benign vehicular nodes which in turn are consumed to report ERMs. RSUs collect ERMs for certain event and figures out if more than one ERM for the same event includes identical token or, if an ERM is sent more than once by the same source. Our proposed scheme preserves privacy in both beacons and ERMs, and provides conditional anonymity where in case of a dispute; malicious attackers are subject to revocation. We also show that our proposed scheme outperforms the previously proposed scheme from security and computational complexity standpoint.</p
Multizentrische Studie zur Hörsturztherapie – Planung und Konzeption
Systemic steroids are widely used worldwide as a standard of care for primary therapy of idiopathic sudden sensorineural hearing loss (ISSHL). The German ISSHL guideline recommends high-dose steroids for primary therapy of ISSHL, without evidence from randomized controlled trials (RCTs). The rationale for the treatment of ISSHL using high dose steroids is only based on retrospective cohort studies. This article describes the planning and initiation of a multicenter, national, randomized, controlled clinical trial entitled Efficacy and safety of high dose glucocorticosteroid treatment for idiopathic sudden sensorineural hearing loss – a three-armed, randomized, triple-blind, multicenter trial (HODOKORT). This clinical trial aims to compare standard dose with two types of high-dose steroids for primary systemic therapy with respect to their efficacy in improving hearing, and thus communication ability, in patients with idiopathic sudden sensorineural hearing loss.
This study is funded by the „Clinical Trials with High Patient Relevance“ research program in the health research framework of the German Federal Ministry of Education and Research. It is one of two studies by the German Study Center of Clinical Trials of the German Society of Otorhinolaryngology, Head and Neck Surgery (DSZ-HNO). Planning and initiation was done in cooperation with the DSZ-HNO, the Coordination Center of Clinical Trials of the Martin-Luther-University Halle-Wittenberg, and the Study Center of the University Hospital Freiburg