scholarly journals SDN Programming for Heterogeneous Switches with Flow Table Pipelining

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Junchang Wang ◽  
Shaojin Cheng ◽  
Xiong Fu
Keyword(s):  
Building Blocks ◽  
Flow Rule ◽  
Link Failures ◽  
Flow Table ◽  
Network Link ◽  
Rule Sets ◽  
Rule Set ◽  
State Changes ◽  
High Level ◽  
Effective Use

High-level programming is one of the critical building blocks of the effective use of software-defined networking (SDN). Existing solutions, however, either (1) cannot utilize the state-of-the-art switches with flow table pipelining, a key technique to prevent flow rule set explosion or (2) force programmers to manually organize and manage hardware flow table pipelines, which is time-consuming and error-prone. This paper presents a high-level SDN programming framework to address these issues. The framework can automatically (1) generate rule sets for heterogeneous switches with different flow table pipelining designs and (2) update installed rules when the network state changes. As a result, the framework can not only generate efficient rule sets for switches but also provide programmers a centralized, intuitive, and hence easy-to-use programming API. Experiments show that the framework can generate compact rule sets that are 29–116 times smaller than those generated by other open-source SDN controllers. Besides, the framework is 5 times faster to recover from network link failures in comparison to other controllers.

scholarly journals Continuous Verification of Network Security Compliance

2021 ◽  
Author(s):  
Claas Lorenz ◽  
Vera Clemens ◽  
Max Schrötter ◽  
Bettina Schnor
Keyword(s):  
Network Security ◽  
Formal Language ◽  
Theorem Prover ◽  
Domain Specific ◽  
Rule Sets ◽  
Rule Set ◽  
Verification Tools ◽  
Data Structures And Algorithms ◽  
Security Compliance ◽  
High Level

Continuous verification of network security compliance is an accepted need. Especially, the analysis of stateful packet filters plays a central role for network security in practice. But the few existing tools which support the analysis of stateful packet filters are based on general applicable formal methods like Satifiability Modulo Theories (SMT) or theorem prover and show runtimes in the order of minutes to hours making them unsuitable for continuous compliance verification.<br>In this work, we address these challenges and present the concept of state shell interweaving to transform a stateful firewall rule set into a stateless rule set. This allows us to reuse any fast domain specific engine from the field of data plane verification tools leveraging smart, very fast, and domain specialized data structures and algorithms including Header Space Analysis (HSA). First, we introduce the formal language FPL that enables a high-level human-understandable specification of the desired state of network security. Second, we demonstrate the instantiation of a compliance process using a verification framework that analyzes the configuration of complex networks and devices - including stateful firewalls - for compliance with FPL policies. Our evaluation results show the scalability of the presented approach for the well known Internet2 and Stanford benchmarks as well as for large firewall rule sets where it outscales state-of-the-art tools by a factor of over 41.

scholarly journals Short communication: The Topographic Analysis Kit (TAK) for TopoToolbox

2018 ◽  
Author(s):  
Adam M. Forte ◽  
Kelin X. Whipple
Keyword(s):  
Open Source ◽  
Domain Knowledge ◽  
Building Blocks ◽  
Topographic Analysis ◽  
Runtime Environment ◽  
Computing Environments ◽  
Programming Skills ◽  
High Level ◽  
Effective Use ◽  
Channel Steepness

Abstract. Quantitative analysis of digital topographic data is an increasingly important part of many studies in the geosciences. Initially, performing these analyses was a niche endeavor, requiring detailed domain knowledge and programming skills, but increasingly broad, flexible, open source code bases have been developed to increasingly democratize topographic analysis. However, many of these still require specific computing environments and/or moderate levels of knowledge of both the relevant programming language and the correct way to take these fundamental building blocks and conduct an efficient and effective topographic analysis. To partially address this, we have written the Topographic Analysis Kit (TAK) which leverages the power of one of these open source libraries, TopoToolbox, to build a series of high-level topographic analysis tools to perform a variety of common topographic analyses, including generation of maps of normalized channel steepness or chi and selection and statistical analysis of populations of watersheds. No programming skills or advanced Matlab capability is required for effective use of TAK. In addition, to expand the utility of TAK, along with the primary functions, which like the underlying TopoToolbox functions require Matlab and several proprietary toolboxes to run, we provide compiled versions of these functions that use the free Matlab Runtime Environment for users who do not have institutional access to Matlab or all of the required toolboxes.

scholarly journals Peer-to-Peer Multicasting Inspired by Huffman Coding

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Bartosz Polaczyk ◽  
Piotr Chołda ◽  
Andrzej Jajszczyk
Keyword(s):  
Source Coding ◽  
Peer To Peer ◽  
Multicast Tree ◽  
Huffman Coding ◽  
Live Streaming ◽  
Link Failures ◽  
Tree Construction ◽  
High Level ◽  
Streaming Multicast ◽  
Effective Use

Stringent QoS requirements of video streaming are not addressed by the delay characteristics of highly dynamic peer-to-peer (P2P) networks. To solve this problem, a novel locality-aware method for choosing optimal neighbors in live streaming multicast P2P overlays is presented in this paper. To create the appropriate multicast tree topology, a round-trip-time (RTT) value is used as a parameter distinguishing peers capabilities. The multicast tree construction is based on the Huffman source coding algorithm. First, a centrally managed version is presented, and then an effective use of a distributed paradigm is shown. Performance evaluation results prove that the proposed approach considerably improves the overlay efficiency from the viewpoint of end-users and content providers. Moreover, the proposed technique ensures a high level of resilience against gateway-link failures and adaptively reorganizes the overlay topology in case of dynamic, transient network fluctuations.

scholarly journals Short communication: The Topographic Analysis Kit (TAK) for TopoToolbox

2019 ◽  
Vol 7 (1) ◽  
pp. 87-95 ◽  
Author(s):  
Adam M. Forte ◽  
Kelin X. Whipple
Keyword(s):  
Domain Knowledge ◽  
Short Communication ◽  
Building Blocks ◽  
Topographic Analysis ◽  
Runtime Environment ◽  
Computing Environments ◽  
Programming Skills ◽  
High Level ◽  
Effective Use ◽  
Channel Steepness

Abstract. Quantitative analysis of digital topographic data is an increasingly important part of many studies in the geosciences. Initially, performing these analyses was a niche endeavor, requiring detailed domain knowledge and programming skills, but increasingly broad, flexible, open-source code bases have been developed to increasingly democratize topographic analysis. However, many of these analyses still require specific computing environments and/or moderate levels of knowledge of both the relevant programming language and the correct way to take these fundamental building blocks and conduct an efficient and effective topographic analysis. To partially address this, we have written the Topographic Analysis Kit (TAK), which leverages the power of one of these open code bases, TopoToolbox, to build a series of high-level topographic analysis tools to perform a variety of common topographic analyses. These analyses include the generation of maps of normalized channel steepness, or χ, and selection and statistical analysis of populations of watersheds. No programming skills or advanced mastery of MATLAB is required for effective use of TAK. In addition – to expand the utility of TAK along with the primary functions, which like the underlying TopoToolbox functions require MATLAB and several proprietary toolboxes to run – we provide compiled versions of these functions that use the free MATLAB Runtime Environment for users who do not have institutional access to MATLAB or all of the required toolboxes.

scholarly journals E-learning-Oriented Software Architecture Design and Case Study

2015 ◽  
Vol 10 (4) ◽  
pp. 59
Author(s):  
Peng Lu ◽  
Xiao Cong ◽  
Dongdai Zhou
Keyword(s):  
Software Architecture ◽  
Building Blocks ◽  
Domain Model ◽  
Learning System ◽  
Application Framework ◽  
Component Library ◽  
E Learning ◽  
The Difference ◽  
High Level

Nowadays, E-learning system has been widely applied to practical teaching. It was favored by people for its characterized course arrangement and flexible learning schedule. However, the system does have some problems in the process of application such as the functions of single software are not diversified enough to satisfy the requirements in teaching completely. In order to cater more applications in the teaching process, it is necessary to integrate functions from different systems. But the difference in developing techniques and the inflexibility in design makes it difficult to implement. The major reason of these problems is the lack of fine software architecture. In this article, we build domain model and component model of E-learning system and components integration method on the basis of WebService. And we proposed an abstract framework of E-learning which could express the semantic relationship among components and realize high level reusable on the basis of informationized teaching mode. On this foundation, we form an E-learning oriented layering software architecture contain component library layer, application framework layer and application layer. Moreover, the system contains layer division multiplexing and was not built upon developing language and tools. Under the help of the software architecture, we could build characterized E-learning system flexibly like building blocks through framework selection, component assembling and replacement. In addition, we exemplify how to build concrete E-learning system on the basis of this software architecture.

scholarly journals The Potential of Building Tourist Cities by Using Existing Resources in Uzbekistan with an Innovative Approach

2020 ◽  
Vol 6 ◽  
Author(s):  
Madina M. Khashimova ◽  
Shakhzod F. Turakulov
Keyword(s):  
Highly Qualified ◽  
Natural Conditions ◽  
Foreign Countries ◽  
Economic Infrastructure ◽  
The Republic ◽  
High Level ◽  
Effective Use ◽  
Steep Slopes ◽  
Training Area

This article reflects the construction of tourist cities using the resources available on the territory of Uzbekistan. The benefits of utilisation for the development of tourism infrastructure from geological cities that are not exploited, included in the available resources, have been analyzed. The high level of efficiency in the use of geological cities is based on the availability of economic infrastructure, which is recognized as the application of this infrastructure in the construction of tourist cities is low in costs. The article shows the specific natural anchors of three ecotouristic objects, the srategic plans for effective use of these anchors. Proposals on the expediency of the establishment of camps, bags, summer recreation zones are included in these facilities. The abundance of excursion facilities and attractions in the objects of ecotourism expressed their views on the possibility of opening remarkable travel destinations. And the steep slopes of the mountain are shown to be a special training area for training highly qualified climbers. Reflecting the peculiarities of the nature of the objects of the ecosystem, the role of these settlements with unique natural conditions in the development of tourism is established. The potential for the construction of such ecotouristic cities in the Republic of Uzbekistan is high, and the growth in the efficiency of the use of such potentials is reported to increase the number of tourists coming from foreign countries to Uzbekistan.

scholarly journals MAPPING OF HIGH VALUE CROPS THROUGH AN OBJECT-BASED SVM MODEL USING LIDAR DATA AND ORTHOPHOTO IN AGUSAN DEL NORTE PHILIPPINES

2016 ◽  
Vol III-7 ◽  
pp. 165-172 ◽  
Author(s):  
Rudolph Joshua Candare ◽  
Michelle Japitana ◽  
James Earl Cubillas ◽  
Cherry Bryan Ramirez
Keyword(s):  
Regularization Parameter ◽  
Optimization Procedure ◽  
Feature Space ◽  
Resource Assessment ◽  
Support Vector ◽  
Lidar Data ◽  
High Resolution Data ◽  
Object Based ◽  
Rule Sets ◽  
Rule Set

This research describes the methods involved in the mapping of different high value crops in Agusan del Norte Philippines using LiDAR. This project is part of the Phil-LiDAR 2 Program which aims to conduct a nationwide resource assessment using LiDAR. Because of the high resolution data involved, the methodology described here utilizes object-based image analysis and the use of optimal features from LiDAR data and Orthophoto. Object-based classification was primarily done by developing rule-sets in eCognition. Several features from the LiDAR data and Orthophotos were used in the development of rule-sets for classification. Generally, classes of objects can't be separated by simple thresholds from different features making it difficult to develop a rule-set. To resolve this problem, the image-objects were subjected to Support Vector Machine learning. SVMs have gained popularity because of their ability to generalize well given a limited number of training samples. However, SVMs also suffer from parameter assignment issues that can significantly affect the classification results. More specifically, the regularization parameter C in linear SVM has to be optimized through cross validation to increase the overall accuracy. After performing the segmentation in eCognition, the optimization procedure as well as the extraction of the equations of the hyper-planes was done in Matlab. The learned hyper-planes separating one class from another in the multi-dimensional feature-space can be thought of as super-features which were then used in developing the classifier rule set in eCognition. In this study, we report an overall classification accuracy of greater than 90% in different areas.

Seismic anisotropy

Geophysics ◽  
2001 ◽  
Vol 66 (1) ◽  
pp. 40-41 ◽  
Author(s):  
Leon Thomsen
Keyword(s):  
Future Development ◽  
Seismic Data ◽  
Seismic Anisotropy ◽  
Practical Interest ◽  
Exploration And Exploitation ◽  
Principal Reason ◽  
The Past ◽  
High Level ◽  
Effective Use

The topic of seismic anisotropy in exploration and exploitation has seen a great deal of progress in the past decade‐and‐a‐half. The principal reason for this is the increased (and increasing) quality of seismic data, of the processing done to it, and of the interpretation expected from it. No longer an academic subject of little practical interest, it is now often viewed as one of the crucial factors which, if not taken into account, severely hampers our effective use of the data. The following brief overview is not intended to be exhaustive, since any such attempt would surely be incomplete. However, it does provide a high‐level survey of the advances seen (at the end of this period) to be important by one who was closely involved, and it directly extrapolates this history to predict the future development of the topic.

Event Detection in Sports Video Based on Generative-Discriminative Models

2011 ◽  
pp. 143-165
Author(s):  
Guoliang Fan ◽  
Yi Ding
Keyword(s):  
Event Detection ◽  
Semantic Analysis ◽  
Building Blocks ◽  
Semantic Space ◽  
Sports Video ◽  
Low Level ◽  
Discriminative Models ◽  
Video Mining ◽  
High Level ◽  
Different Levels

Semantic event detection is an active and interesting research topic in the field of video mining. The major challenge is the semantic gap between low-level features and high-level semantics. In this chapter, we will advance a new sports video mining framework where a hybrid generative-discriminative approach is used for event detection. Specifically, we propose a three-layer semantic space by which event detection is converted into two inter-related statistical inference procedures that involve semantic analysis at different levels. The first is to infer the mid-level semantic structures from the low-level visual features via generative models, which can serve as building blocks of high-level semantic analysis. The second is to detect high-level semantics from mid-level semantic structures using discriminative models, which are of direct interests to users. In this framework we can explicitly represent and detect semantics at different levels. The use of generative and discriminative approaches in two different stages is proved to be effective and appropriate for event detection in sports video. The experimental results from a set of American football video data demonstrate that the proposed framework offers promising results compared with traditional approaches.

Field Programmable Photonic Gate Arrays

2020 ◽  
pp. 301-330
Author(s):  
José Capmany ◽  
Daniel Pérez
Keyword(s):  
Building Blocks ◽  
Design Flow ◽  
Power Splitting ◽  
Gate Arrays ◽  
Field Programmable ◽  
Reconfigurable Processing ◽  
Gate Array ◽  
Photonic Interconnects ◽  
High Level ◽  
Electronic Field

The field programmable photonic gate array (FPPGA) is an integrated photonic device/subsystem that operates similarly to a field programmable gate array in electronics. It is a set of programmable photonics analogue blocks (PPABs) and of reconfigurable photonic interconnects (RPIs) implemented over a photonic chip. The PPABs provide the building blocks for implementing basic optical analogue operations (reconfigurable/independent power splitting and phase shifting). Broadly they enable reconfigurable processing just like configurable logic elements (CLE) or programmable logic blocks (PLBs) carry digital operations in electronic FPGAs or configurable analogue blocks (CABs) carry analogue operations in electronic field programmable analogue arrays (FPAAs). Reconfigurable interconnections between PPABs are provided by the RPIs. This chapter presents basic principles of integrated FPPGAs. It describes their main building blocks and discusses alternatives for their high-level layouts, design flow, technology mapping and physical implementation. Finally, it shows that waveguide meshes lead naturally to a compact solution.

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