Open-Source Software Defined Networking Controllers:State-of-the-Art,Challenges and Solutions for Future Network Providers

Software Defined Networking(SDN)is programmable by separation of forwarding control through the centralization of the controller.The controller plays the role of the‘brain’that dictates the intelligent part of SDN technology.Various versions of SDN controllers exist as a response to the diverse demands and functions expected of them.There are several SDN controllers available in the open market besides a large number of commercial controllers;some are developed tomeet carrier-grade service levels and one of the recent trends in open-source SDN controllers is the Open Network Operating System(ONOS).This paper presents a comparative study between open source SDN controllers,which are known as Network Controller Platform(NOX),Python-based Network Controller(POX),component-based SDN framework(Ryu),Java-based OpenFlow controller(Floodlight),OpenDayLight(ODL)and ONOS.The discussion is further extended into ONOS architecture,as well as,the evolution of ONOS controllers.This article will review use cases based on ONOS controllers in several application deployments.Moreover,the opportunities and challenges of open source SDN controllers will be discussed,exploring carriergrade ONOS for future real-world deployments,ONOS unique features and identifying the suitable choice of SDN controller for service providers.In addition,we attempt to provide answers to several critical questions relating to the implications of the open-source nature of SDN controllers regarding vendor lock-in,interoperability,and standards compliance,Similarly,real-world use cases of organizations using open-source SDN are highlighted and how the open-source community contributes to the development of SDN controllers.Furthermore,challenges faced by open-source projects,and considerations when choosing an open-source SDN controller are underscored.Then the role of Artificial Intelligence(AI)and Machine Learning(ML)in the evolution of open-source SDN controllers in light of recent research is indicated.In addition,the challenges and limitations associated with deploying open-source SDN controllers in production networks,how can they be mitigated,and finally how opensource SDN controllers handle network security and ensure that network configurations and policies are robust and resilient are presented.Potential opportunities and challenges for future Open SDN deployment are outlined to conclude the article.

Web service based spatial forest information system using an open source software approach

For technical and other reasons there is a dilemma that data providers cannot find an appropriate way to redistribute spatial forest data and data users who need spatial data cannot access and integrate available forest resources information. To overcome this dilemma, this paper proposed a spatial forest information system based on Web service using an open source software approach. With Web service based architecture, the system can enable interoperability, integrate Web services from other application servers, reuse codes, and shorten the development time and cost. At the same time, it is possible to extend the local system to a regional or national spatial forest information system. The growth of Open Source Software （OSS） provides an alternative choice to proprietary software for operating systems, web servers, Web-based GIS applications and database management systems. Using open source software to develop spatial forest information systems can greatly reduce the cost while providing high performance and sharing spatial forest information. We chose open source software to build a prototype system for Xixia County, Henan Province, China. By integrating OSS packages Deegree and UMN MapServer which are compliant to the OGC open specifications, the prototype system enables users to access spatial forest information and travelling information of Xixia County which come from two different data servers via a standard Web browser and promotes spatial forest information sharing.

Web Based GIS for Tourism Development Using Effective Free and Open Source Software Case Study: Gondor Town and Its Surrounding Area, Ethiopia

Tourism in developing countries are some means of solving their economic problems and improving live standards of people and creates job opportunity for the host people in getting additional income and improve the developments of the country. The result of tourism in terms of environmental, cultural, economic and social aspects has a greater effect for Ethiopia. Gondar, the center of Ethiopian art and culture, is famous in its many Imperial castles and the design and decoration of its churches. This land of castles and churches was founded by Emperor Fasiladas in 1930s and served as tourist attraction sites all over the world. The main challenge to attract international tourists in the study area is Scarce and insufficient promotion of the tourist attraction sites, Lack of broad information based on the internet about tourism information, and lack of organized information about tourism facilities & destinations. This study tries to identify tourist attraction elements of Gondor town and its surrounding area & to identify non spatial data’s essential for touristic activities to develop & propose a web based GIS portal for the improvement of tourism activity in the town. The main target of developing a web based GIS interactive map is to promote and improve tourism industry of the area. It has been produced using free and open source software’s for fast processing, displaying, sharing, and distribution of tourism information using world wide web. For the web services PHP, HTML script language and QGIS2leaflet plugins are used in the development of web GIS portal.

An Open CAM System for Dentistry on the Basis of China-made 5-axis Simultaneous Contouring CNC Machine Tool and Industrial CAM Software

China-made 5-axis simultaneous contouring CNC machine tool and domestically developed industrial computer-aided manufacture （CAM） technology were used for full crown fabrication and measurement of crown accuracy, with an attempt to establish an open CAM system for dental processing and to promote the introduction of domestic dental computer-aided design （CAD）/CAM system. Commercially available scanning equipment was used to make a basic digital tooth model after preparation of crown, and CAD software that comes with the scanning device was employed to design the crown by using domestic industrial CAM software to process the crown data in order to generate a solid model for machining purpose, and then China-made 5-axis simultaneous contouring CNC machine tool was used to complete machining of the whole crown and the internal accuracy of the crown internal was measured by using 3D-MicroCT. The results showed that China-made 5-axis simultaneous contouring CNC machine tool in combination with domestic industrial CAM technology can be used for crown making and the crown was well positioned in die. The internal accuracy was successfully measured by using 3D-MicroCT. It is concluded that an open CAM system for den-tistry on the basis of China-made 5-axis simultaneous contouring CNC machine tool and domestic industrial CAM software has been established, and development of the system will promote the introduction of domestically-produced dental CAD/CAM system.

Evaluation and Customization of Different Open Source Desktop GIS Software

This paper gave a general evaluation on existing three popular free and open source desktop GIS projects,according to the selected evaluation criteria.To further the understanding of the open source software,this paper also presented a customization example of QGIS with python and PyQT.

Open Source GIS Software Options for Forestry Education in Papua New Guinea

Although open source softwares (OSS) for GIS and Remote Sensing are rapidly expanding and improving in the global context, there has been uncertainty at higher education institutions in developing countries, such as the department of forestry (Dfo) at Unitech, Papua New Guinea (PNG), regarding appropriate GIS softwares and hardware to acquire and use for teaching and research purposes. The paper briefly describes the characteristics of some mature OSS and discusses their main capabilities, advantages and disadvantages. Their adoption in the Dfo curricula may be advantageous in the long term, considering issues of learning curve steepness, versatility, affordability, effectiveness, and documentation available on them.

Code Reviewer Intelligent Prediction in Open Source Industrial Software Project

Currently, open-source software is gradually being integrated into industrial software, while industry protocolsin industrial software are also gradually transferred to open-source community development. Industrial protocolstandardization organizations are confronted with fragmented and numerous code PR (Pull Request) and informalproposals, and differentworkflowswill lead to increased operating costs. The open-source community maintenanceteam needs software that is more intelligent to guide the identification and classification of these issues. To solvethe above problems, this paper proposes a PR review prediction model based on multi-dimensional features. Weextract 43 features of PR and divide them into five dimensions: contributor, reviewer, software project, PR, andsocial network of developers. The model integrates the above five-dimensional features, and a prediction model isbuilt based on a Random Forest Classifier to predict the review results of PR. On the other hand, to improve thequality of rejected PRs, we focus on problems raised in the review process and review comments of similar PRs.Wepropose a PR revision recommendation model based on the PR review knowledge graph. Entity information andrelationships between entities are extracted from text and code information of PRs, historical review comments,and related issues. PR revisions will be recommended to code contributors by graph-based similarity calculation.The experimental results illustrate that the above twomodels are effective and robust in PR review result predictionand PR revision recommendation.

Temporal Patterns of Software Evolution Defects: A Comparative Analysis of Open Source and Closed Source Projects

This study examines temporal patterns of software systems defects using the Autoregressive Integrated Moving Average (ARIMA) approach. Defect reports from ten software application projects are analyzed;five of these projects are open source and five are closed source from two software vendors. Across all sampled projects, the ARIMA time series modeling technique provides accurate estimates of reported defects during software maintenance, with organizationally dependent parameterization. In contrast to causal models that require extraction of source-code level metrics, this approach is based on readily available defect report data and is less computation intensive. This approach can be used to improve software maintenance and evolution resource allocation decisions and to identify outlier projects—that is, to provide evidence of unexpected defect reporting patterns that may indicate troubled projects.

Call for Implementation: A New Software Development Mode for Leveraging the Resources of Open Community

With the growth of the internet and open software, there are additional software developers available from the open community that can participate in the development of software application systems. Aiming to leverage these resources, a new development model, CFI (call for implementation), is proposed. The basic idea of CFI is to publish some part of a software project to the open community, whole or part, in certain phases of the software development lifecycle to call for implementation. This paper discusses the basic concept and method for a software development process in CFI mode. Two different modes of CFI with different granularities are analyzed. And one of the CFI modes, fine-granularity-CFI mode, is thoroughly discussed including the main methods and basic steps. To verify the ideas a pilot project, an online store system, is built up with the CFI development process. The online store system takes the traditional Model-View-Control architecture and some common technologies such as Struts, Hibernate, Spring are used. The result shows that this new kind of software development mode is feasible though there are many problems that are still requiring further study.

Component-Oriented Reliability Analysis Based on Hierarchical Bayesian Model for an Open Source Software

The successful experience of adopting distributed development models in such open source projects includes GNU/Linux operating system, Apache HTTP server, Android, BusyBox, and so on. The open source project contains special features so-called software composition by which several geographically-dispersed compo-nents are developed in all parts of the world. We propose a method of component-oriented reliability as-sessment based on hierarchical Bayesian model and Markov chain Monte Carlo methods. Especially, we fo-cus on the fault-detection rate for each component reported to the bug tracking system. We can assess the reliability for the whole open source software system by using the confidence interval for each component. Also, we analyze actual software fault-count data to show numerical examples of reliability assessment for OSS.

Use of Open Source Software for the Development of Web GIS for Accessibility to Tourist Attractions

Based on the concepts of social inclusion, universal design and accessibility, this paper aims to describe the stages of the development and implementation of a Web GIS （geographic information system for the internet） based on OS （open source） software The Web GIS developed is called ＂accessibility to Campinas tourist attractions＂, which provides information about cultural and natural attractions in Campinas/SP-Brazil, especially for people with disabilities or reduced mobility that prevents access these sites via public and private transportation. The verification of the existence or lack of accessibility equipment at bus stops and parking areas close to tourist attractions relies on current legislation （NBR 9050/1994） that establishes the right to accessibility for disabled people to transportation, local culture and leisure. An application that facilitates this recognition with low operating costs and high performance was developed using the OS software Quantum GIS 1.0.2, Apache 2.2.4, Mapserver 5.0.2, I3GEO 4.0, PostgreSQL 8.3 and PostGIS 1.3.5. This software is able to integrate the management of tourist areas and the advertisement of tourist information regarding accessibility devices at sights recognized as tourist attractions by Campinas city hall.

Application of UG Software in Mechanical Design

UG software is powerful,and has been widely applied in machine design.The following is an analysis of the development of UG software.It also analyzes the characteristics of use and analyzes the specific application,hoping to give some references to the people concerned.

Social Computing in Open Source Community:A Study of Software Reuse

Software projects are not developed in isolation but often build upon other open source resources. These projects form a kind of reference ecosystem regarded as a software world. Most of social computing works focus on social networks such as Facebook and weibo to mine information. However, few previous works analyze Open Source Community which could help developers conduct collaborative development. In this paper, we model the Java reference ecosystem as a network based on the reuse relationships of GitHub-hosted Java projects and analyze the characteristics and the patterns of this reference ecosystem by using community detection and pattern discovery algorithms. Our study indicates that (1) Developers prefer to reuse software limited in only a small part of projects with cross cutting functionality or advanced applications. (2) Developers usually select software reused with similar function widely depending on different requirements, resulting to different patterns. Based on these collective intelligence, our study opens up several possible future directions of reuse recommendation,which are considered as guidance of collaborative development.

Software Metric Analysis of Open-Source Business Software

Over the past decade, open-source software use has grown. Today, many companies including Google, Microsoft, Meta, RedHat, MongoDB, and Apache are major participants of open-source contributions. With the increased use of open-source software or integration of open-source software into custom-developed software, the quality of this software component increases in importance. This study examined a sample of open-source applications from GitHub. Static software analytics were conducted, and each application was classified for its risk level. In the analyzed applications, it was found that 90% of the applications were classified as low risk or moderate low risk indicating a high level of quality for open-source applications.

UG/OPEN在车身覆盖件模具修边线中的应用

针对目前在车身覆盖件拉深模具开发设计中确定修边线时大多采用手动截面求取修边线的方法比较费时的现状,提出利用二次开发工具—UG/OPEN开发自动确定车身覆盖件拉深模具修边线程序的方法来解决这一问题。根据覆盖件拉深成形后,后续工序基本不再产生塑性变形,从而近似地认为从覆盖件工艺补充面与翻边部分交线处以外材料的长度基本不变的思路。提出了开发自动确定车身覆盖件拉深模具修边线程序的实现原理,并强调借助CAE技术来修正结果。开发出了基于UG/OPEN的自动确定车身覆盖件拉深模具修边线的程序。并成功地将所开发的工具应用于某轿车车身覆盖件拉深模具修边线的确定,取得了显著的效果,缩短了模具开发设计的周期。

基于UG/OPEN API的蜗杆传动参数化系统开发

介绍了利用UG/OPEN API开发蜗轮蜗杆参数化系统的方法。以VC为编程语言,实现了蜗轮齿面接触强度、齿根弯曲强度设计计算和校核,并建立以蜗轮蜗杆材料、特征参数为中心的数据库系统。本文以开发阿基米德蜗杆参数化系统为例,探讨了UG/OPEN API三维参数化建模的关键技术。

基于UG/Open联合开发的叶片工序模型造型系统

叶片造型是一个相对复杂的过程,通用的CAD平台并不适合叶片造型。文章应用UG/Open提供的多种开发工具,构建了基于UG的叶片CAD造型系统。通过对CAD平台的二次开发,提供了一种三维叶片工序数模的构建方法,简化了叶片造型过程,实现了航空发动机叶片的快速造型。以某型压气机叶片为例阐述了造型过程。该系统已得到实际应用,实践证实该系统具有造型方便、快捷等特点,且对于不同类型的叶片具有一定的适应性,满足不同用户的需求。

ODBC技术及UG/OPENAPI在汽车模具标准件库中的应用

详细阐述了ODBC技术的概念以及体系结构关系,对UG/OpenAPI的二次开发功能也进行了简单的介绍。最后给出了二者进行联合开发的应用实例。

基于VC++的UG二次开发技术UG/Open MenuScript的应用

首先介绍UG/Open的开发工具,并具体给出菜单制作技术的具体步骤。在此基础上,借助整体叶轮加工模块的开发,详细阐述在VC++6.0开发平上,利用UG/Open API函数实现UG菜单的用户化定制,结合实例分析UG菜单的制作过程,给出菜单制作的具体函数代码,对UG菜单的制作具有很好的指导意义。此开发技术可以实现对UG系统的功能集成,使之与UG系统达到无缝集成。