scholarly journals A Lightweight SDN Fingerprint Attack Defense Mechanism Based on Probabilistic Scrambling and Controller Dynamic Scheduling Strategies

2021 ◽  
Vol 2021 ◽  
pp. 1-23
Author(s):  
Tao Wang ◽  
Hongchang Chen
Keyword(s):  
Network Performance ◽  
Dynamic Scheduling ◽  
Defense Mechanism ◽  
Negative Impact ◽  
Scheduling Strategy ◽  
Security Issues ◽  
Different Types ◽  
Network Flexibility ◽  
Benefits And Costs ◽  
Attack Time

Software-defined networking (SDN) decouples the control plane from the data plane, which increases network flexibility and programmability. However, the “three-layer two-interface” architecture of SDN introduces new security issues. Attackers can collect fingerprint information (such as network types, controller types, and critical flow rules) by analyzing round-trip time (RTT) distribution of test packets. In order to defend against the fingerprint attack with limited attack time, we first design a probabilistic scrambling strategy. This strategy not only interferes with the delay distribution of probe packets in attack flow but also reduces the negative impact on the performance of legal packets in normal flow. However, if fingerprint attackers have unlimited attack time, it is not enough to defend against the attack only by this strategy. Therefore, we further propose a controller dynamic scheduling strategy to change SDN fingerprint information actively. Because scheduling different types of controllers to work in different periods will generate costs, the scheduling strategy is also responsible for determining the optimal switching time point to balance security benefits and costs. At last, we implement the defense mechanism on different types of controllers and verify its effectiveness in experimental scenarios. The experimental results show that the mechanism can effectively hide the SDN fingerprint information while reducing the negative impact on network performance.

Competition Policy and Price Fixing

2013 ◽  
Author(s):  
Louis Kaplow
Keyword(s):  
Competition Policy ◽  
Competition Law ◽  
Direct Approach ◽  
Social Harm ◽  
Systematic Analysis ◽  
Oligopoly Theory ◽  
Different Types ◽  
Error Costs ◽  
Benefits And Costs ◽  
Desirable Behavior

Throughout the world, the rule against price fixing is competition law's most important and least controversial prohibition. Yet there is far less consensus than meets the eye on what constitutes price fixing, and prevalent understandings conflict with the teachings of oligopoly theory that supposedly underlie modern competition policy. This book offers a fresh, in-depth exploration of competition law's horizontal agreement requirement, presents a systematic analysis of how best to address the problem of coordinated oligopolistic price elevation, and compares the resulting direct approach to the orthodox prohibition. The book elaborates the relevant benefits and costs of potential solutions, investigates how coordinated price elevation is best detected in light of the error costs associated with different types of proof, and examines appropriate sanctions. Existing literature devotes remarkably little attention to these key subjects and instead concerns itself with limiting penalties to certain sorts of interfirm communications. Challenging conventional wisdom, the book shows how this circumscribed view is less well grounded in the statutes, principles, and precedents of competition law than is a more direct, functional proscription. More important, by comparison to the communications-based prohibition, the book explains how the direct approach targets situations that involve both greater social harm and less risk of chilling desirable behavior—and is also easier to apply.

scholarly journals Threat or Corrective? Assessing the Impact of Populist Parties in Government on the Qualities of Democracy: A 19-Country Comparison

2021 ◽  
pp. 1-21
Author(s):  
Davide Vittori
Keyword(s):  
Negative Impact ◽  
Quality Of Democracy ◽  
Clear Cut ◽  
Liberal Democratic ◽  
Country Comparison ◽  
Democratic Regimes ◽  
Different Types ◽  
The Impact

Abstract Scholars have long debated whether populism harms or improves the quality of democracy. This article contributes to this debate by focusing on the impact of populist parties in government. In particular, it inquires: (1) whether populists in government are more likely than non-populists to negatively affect the quality of democracies; (2) whether the role of populists in government matters; and (3) which type of populism is expected to negatively affect the quality of liberal-democratic regimes. The results find strong evidence that the role of populists in government affects several qualities of democracy. While robust, the findings related to (2) are less clear-cut than those pertaining to (1). Finally, regardless of their role in government, different types of populism have different impacts on the qualities of democracy. The results show that exclusionary populist parties in government tend to have more of a negative impact than other forms of populism.

scholarly journals Assessment of the mercury contamination of landfilled and recovered foundry waste – a case study

2021 ◽  
Vol 19 (1) ◽  
pp. 462-470
Author(s):  
Marta Bożym ◽  
Beata Klojzy-Karczmarczyk
Keyword(s):  
Negative Impact ◽  
Mercury Content ◽  
Mercury Contamination ◽  
Reference Level ◽  
Organic Carbon Content ◽  
Foundry Sands ◽  
Industrial Sites ◽  
Different Types ◽  
Main Component

Abstract Environmental pollution by mercury is a local problem in Poland and concerns mainly industrial sites. Foundry waste are usually characterized by low mercury content compared to other heavy metals. Spent foundry sands with low content of Hg are the main component of foundry waste. However, Hg may be present in foundry dust, which may also be landfilled. Due to Hg toxicity, even a minimal content may have a negative impact on biota. This study focuses on assessing the mercury content of landfilled foundry waste (LFW), to assess its toxicity. Currently tested waste is recovered and reused as a road aggregate. The results were compared with the mercury content of local soils as the reference level. Waste samples were taken from foundry landfill. The mercury content, fractional composition, organic matter (OM) and total organic carbon content, pH and elementary composition of waste were analysed. It was found that the mercury content in LFW was very low, at the level of natural content in soils and did not pose a threat to the environment. The statistical analysis shows that mercury was not associated with OM of the waste, in contrast to soils, probably due to different types of OM in both materials.

“De terughaalactie geld alleen voor de hierboven afgebelede pizza’s geldig.”

2015 ◽  
Vol 43 (3) ◽  
Author(s):  
Mariet Raedts ◽  
Irene Roozen
Keyword(s):  
Negative Impact ◽  
Purchase Intentions ◽  
The Other ◽  
Product Recalls ◽  
Negative Consequences ◽  
Product Recall ◽  
Brand Evaluations ◽  
Different Types

Consumers’ responses to product recalls with language errors Consumers’ responses to product recalls with language errors Product recall notices not only warn consumers for faulty products, they also limit the damage which may be caused to the company. But what happens when the product recall notice itself contains errors? This study investigated the effects of three different types of language errors: typographical errors, verb errors and sentence errors. Four versions of a product recall were created. The control condition contained no errors. The other three versions contained either five typos, five grammatical conjugation errors or five poorly formed sentences. Participants (N = 710) were randomly assigned to one of the four conditions. Results indicate that participants who detected the errors, had lower attitudes towards the advertisement and the company than participants in the control condition and participants who failed to detect the errors. Poorly formed sentences also had a negative impact on consumers’ brand evaluations and their future product purchase intentions. Hence, language errors in product recall notices can have negative consequences for companies.

scholarly journals Analysis of rail yard and terminal performances

2014 ◽  
Vol 8 (2) ◽  
pp. 178-200 ◽  
Author(s):  
Marin Marinov ◽  
Leonardo Di Giovanni ◽  
Giulia Bellisai ◽  
Julian Clevermann ◽  
Anastasia Mastellou ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Critical Points ◽  
Network Performance ◽  
Logical Consequence ◽  
Time Frame ◽  
Key Factors ◽  
Railway Network ◽  
Rail Infrastructure ◽  
Different Types ◽  
Junction Points

One of the latest trends in the transport field is the increasing interest for the rejuvenation of the railway. It is considered to be a logical consequence of the gradual switch towards a more sustainable future in transports. Terminals and stations are considered to be the junction points between the various lines that constitute the railway network and can simply be described as points of arrival, departure and interchange of passengers or commodities. The most commonly used indicators that measure the level of their performance are time and cost. This study aims at exploring possible improvements that could be implemented to the infrastructure and the operation of terminals and stations in order to increase the efficiency level. Firstly, drawing upon grounded theory about rail infrastructure and terminals, a description is conducted, followed by a comparative analysis of the different types of existing terminals and stations. Secondly, the suggested improvements are presented in accordance with their time frame completion. The main contribution of this study is to illustrate the high significance of terminals, stations and yards, acknowledging them as crucial parts of the railway network, because as characterized and demonstrated in this study, their performance are key factors to the whole network performance, making the identification of their critical points and respective possible solutions, the final objective of this paper. In addition to this, emphasis is given to the need of improving and developing the existing terminal infrastructure and operations.

scholarly journals Context-Based Topology Control for Wireless Mesh Networks

2016 ◽  
Vol 2016 ◽  
pp. 1-16
Author(s):  
Pragasen Mudali ◽  
Matthew Olusegun Adigun
Keyword(s):  
Topology Control ◽  
Wireless Mesh Network ◽  
Network Performance ◽  
Mesh Networks ◽  
Negative Impact ◽  
Mesh Network ◽  
Adjustment Process ◽  
Spatial Reuse ◽  
Test Bed ◽  
Wireless Mesh

Topology Control has been shown to provide several benefits to wireless ad hoc and mesh networks. However these benefits have largely been demonstrated using simulation-based evaluations. In this paper, we demonstrate the negative impact that the PlainTC Topology Control prototype has on topology stability. This instability is found to be caused by the large number of transceiver power adjustments undertaken by the prototype. A context-based solution is offered to reduce the number of transceiver power adjustments undertaken without sacrificing the cumulative transceiver power savings and spatial reuse advantages gained from employing Topology Control in an infrastructure wireless mesh network. We propose the context-based PlainTC+ prototype and show that incorporating context information in the transceiver power adjustment process significantly reduces topology instability. In addition, improvements to network performance arising from the improved topology stability are also observed. Future plans to add real-time context-awareness to PlainTC+ will have the scheme being prototyped in a software-defined wireless mesh network test-bed being planned.

scholarly journals A Study on Pattern Recognition with the Histograms of Oriented Gradients in Distorted and Noisy Images

2020 ◽  
Vol 26 (4) ◽  
pp. 454-478
Author(s):  
Andrzej Bukała ◽  
Michał Koziarski ◽  
Bogusław Cyganek ◽  
Osman Koç ◽  
Alperen Kara
Keyword(s):  
Pattern Recognition ◽  
Negative Impact ◽  
Quality Data ◽  
High Quality ◽  
Denoising Method ◽  
High Quality Data ◽  
Histograms Of Oriented Gradients ◽  
Different Types ◽  
Simple Implementation ◽  
Salt And Pepper

Histograms of oriented gradients (HOG) are still one of the most frequently used low-level features for pattern recognition in images. Despite their great popularity and simple implementation performance of the HOG features almost always has been measured on relatively high quality data which are far from real conditions. To fill this gap we experimentally evaluate their performance in the more realistic conditions, based on images affected by different types of noise, such as Gaussian, quantization, and salt-and-pepper, as well on images distorted by occlusions. Different noise scenarios were tested such anti-distortions during training as well as application of a proper denoising method in the recognition stage. As underpinned with experimental results, the negative impact of distortions and noise on object recognition with HOG features can be significantly reduced by employment of a proper denoising strategy.

STUDY ON EFFECTS OF DISTRUTIVE AGENTS ON THE ARTWORKS

2017 ◽  
Vol 31 (1) ◽  
pp. 75-81
Author(s):  
Valeria Mirela Brezoczki ◽  
◽  
Emese Bonta ◽  
Keyword(s):  
Negative Impact ◽  
Art Museum ◽  
External Factors ◽  
Cultural Value ◽  
Negative Effects ◽  
Active Monitoring ◽  
Baia Mare ◽  
Different Types ◽  
The Impact ◽  
Over Time

The paper describes a series of effects created by the impact of environmental factors on artworks in museums, as well as the way that active monitoring of these destructive agents (temperature and relative humidity) is done. Over time, artefacts exhibited within museums are subject to a series of degradations caused by external factors (air components, humidity, temperature, sunlight, bacteria, molds or fungi etc.), which can leave a negative impact on these goods with cultural value. The main observed negative effects are directly and intimate related to the deterioration of wood sculptures by the occurrence of cracks and the installation of different types of bacteria; the appearance of brownish-red spots on the surface of the paper and the increase in its reliability; various types of corrosion of artworks from different metals; color losses and cracks on paintings etc. The study brings to the fore the damaging effects produced on the different cultural works hosted within the County Art Museum - Art Center Baia Mare.

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