Software Defined Networking (SDN) is an emerging paradigm, which brings the network innovation and attracts both the industries and researchers. SDN is a programmable network model that separates the control logic from the forwarding plane. The centralize control plane takes care of all networking resources. The attackers target the SDN controller, to paralyze the logic plane that is considered as the brain of the network which provides a lot of benefits. However, due to the characteristics the control plane becomes the attractive target of security attacks for the adversaries. One of the most known threats is Distributed Denial-of-Service (DDoS) attacks with the goal to exhausting network resources by sending heavy traffic to them, causing network congestion. Since SDN was proposed, DDoS attack has become a popular research field in SDN security and many researchers have been presented DDoS attacks detection, prevention and mitigation solutions in SDN environment using different methods. This paper surveys the previous researches in DDoS attacks detection and mitigation based methods available in SDN environment.
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This paper presents a sensor fusion analysis of a teleoperated unmanned vehicle that is integrated with a driving simulator. The master system has a host computer and a simulator and the slave system is equipped with an electronic vehicle system. Experimental results are shown concerning brake range, handling performance and acceleration
Even though auctions are capturing an increasing share of commerce, they are typically treated in the theoretical economics literature as isolated. That is, an auction is typically treated as a single seller facing multiple buyers or as a single buyer facing multiple sellers. In this paper, we review the state of the art of competition between auctions. We consider three different types of competition: competition between auctions, competition between formats, and competition between auctioneers vying for auction traffic. We highlight the newest experimental, statistical and analytical methods in the analysis of competition between auctions.
The purpose of this study was to kinematically analyze the differences between short(2.17 m) and long(10.94 m) putting stroke motions. Thirteen male professional golfers were participated in this study. Experiment was conducted on the artificial grass mat in the gymnasium. Kinematic data were collected by the 60 Hz Kwon3D motion analysis system. Differences were compared by SPSS paired t-test and one-way ANOVA. Duncan was used for post-hoc test and a
Delivery of gold nanoparticles (AuNPs) to retinal ganglion cells is gaining attention as a therapeutic and diagnostic approach for retinal diseases. However, intravitreal injection of AuNPs is invasive and thus is not optimal. Focused ultrasound with microbubbles (FUS) is a non-invasive method for systemic delivery of viral vectors to retinal Müller glia; however, whether metallic nanoparticles of various sizes and shapes can be delivered via FUS remains unknown. Here, we report FUS-assisted delivery of AuNPs of varying shapes and sizes to retinal ganglion cells. FUS can also deliver dextran (70kDa) to the retinal layer, especially the retinal ganglion cell layer and inner nuclear layer cells. Two-photon microscopic imaging of AuNPs injected into the retinal ganglion cell layer confirms that spherical- and rod-shaped AuNPs with maximum dimensions <80nm are effectively delivered without damage. The amount of detected AuNPs varies with size. Spherical nanoparticles of small diameter (10nm) are ~20-fold more abundant than larger nanoparticles (55nm). Our findings provide a novel approach for delivering nanometer-sized metallic and organic nanomaterials without damaging retinal tissue
The authors model how to measure consumer willingness to pay (WTP) using an English, or ascending first-price, auction based on two general bidding premises: No bidder bids more than his or her WTP, and no bidder allows a rival bidder to win at a price that he or she is willing to beat. In other words, the authors propose a “no-regret” rule in bidding. They impose no other restrictive assumptions on “maximands” or the bidders' behaviors in a competitive auction context. The authors model WTP as having two components: a pure product feature component and one based on the auction market environment. The latter includes bidder experience, seller reputation, and measures for competition among bidders and items. The proposed model is general enough to include a “buy-it-now” (equivalent to a posted price) auction mechanism. The authors use data on notebook auctions from one of the largest Internet auction sites in Korea. They find that most product characteristics matter in the expected ways. There are two additional primary findings: First, WTP declines as more similar items are concurrently listed with the focal item; there is an additional effect if these similar items also belong to the same brand. Therefore, market thickness matters for consumer WTP. Second, more extensive site surfing and bidding histories lead to lower WTP, implying that search costs and experience matter in bidding. As specific substantive benefits, the authors demonstrate how sellers can calculate changes in WTP and, thus, the expected revenue as the number of concurrently available similar items varies.
In a personal area network (PAN) with wearable devices, the security of a file stored is an important concern. Secret sharing has received considerable attention for handling security, as it guarantees confidentiality and integrity even when some devices, whose count when taken together less than the minimum threshold, are compromised, lost, or stolen. However, because traditional secret sharing has tremendous computational overhead and requires a large storage space, it is not appropriate for battery-powered wearable devices. To overcome this limitation, combinatorial-based file sharing is proposed. However, this incurs another efficiency problem, as preparation of file storage and retrieval involves computational costs. Additionally, this file sharing has been designed without considering an environment with heterogeneous wearable devices. To overcome the aforementioned problems, we first propose a new fog network model that delegates the calculation for the preparation of file storage and retrieval to a fog node, such as a smartphone or tablet PC. A fog node has relatively faster operational ability and larger battery capacity, and hence the resources of the devices in the PAN can be managed efficiently. Additionally, we propose a new algorithm that generates file shares by considering the heterogeneous characteristics of wearable devices. In particular, we consider the factors of storage capacity and network speed to determine the sizes of the file shares. We demonstrate that our proposed model manages the file stored efficiently, using mathematical analysis and simulations.
The purpose of this study was to investigate comparative analysis of the vertical ground reaction force variables during landing from vertical jump blocking in volleyball through GRF analysis system. The subjects participated in this study were 6 male university volleyball player and 6 male acted as a control group. The results are as follows: 1. The skilled group was longer than the unskilled group in flight time during vertical jump blocking. 2. The skilled group was faster than the unskilled group in tFz2 during landing from vertical jump blocking. 3. The skilled group was higher than the unskilled group in Fz2 during landing from vertical jump blocking. 4. The skilled group was higher than the unskilled group in Fz2LR during landing from vertical jump blocking. 5. The skilled group was higher than the unskilled group in impulse during landing from vertical jump blocking. Consequently, during landing from vertical jump, the landing strategy of the skilled group was found as a form of a stiff landing. Therefore, this landing strategy will be required to strengthen of hip and knee extensors and ankle plantar flexors for injury prevention.
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