Ecological controls on biogeochemical fluxes in the western Antarctic Peninsula studied with an inverse foodweb model

Sea ice in the western Antarctic Peninsula （WAP） region is both highly variable and rapidly changing. In the Palmer Station region, the ice season duration has decreased by 92 d since 1978. The sea-ice changes affect ocean stratification and freshwater balance and in turn impact every component of the polar marine ecosystem. Long-term observations from the WAP nearshore and offshore regions show a pattern of chlorophyll （Chl） variability with three to five years of negative Chl anomalies interrupted by one or two years of positive anomalies （high and low Chl regimes）. Both field observations and results from an inverse food-web model show that these high and low Chl regimes differed significantly from each other, with high primary productivity and net community production （NCP） and other rates associated with the high Chl years and low rates with low Chl years. Gross primary production rates （GPP） averaged 30 mmolC.m^-2.d^-1 in the low Chl years and 100 mmolC.m-2.d1 in the high Chl years. Both large and small phytoplankton were more abundant and more productive in high Chl years than in low Chl years. Similarly, krill were more important as grazers in high Chl years, but did not differ from microzooplankton in high or low Chl years. Microzooplankton did not differ between high and low Chl years. Net community production differed significantly between high and low Chl years, but mobilized a similar proportion of GPP in both high and low Chl years. The composition of the NCP was uniform in high and low Chl years. These results emphasize the importance of microbial components in the WAP plankton system and suggest that food webs dominated by small phytoplankton can have pathways that funnel production into NCP, and likely, export.

Framework to Model User Request Access Patterns in the World Wide Web

In this paper, we present a novel approach to model user request patterns in the World Wide Web. Instead of focusing on the user traffic for web pages, we capture the user interaction at the object level of the web pages. Our framework model consists of three sub-models: one for user file access, one for web pages, and one for storage servers. Web pages are assumed to consist of different types and sizes of objects, which are characterized using several categories: articles, media, and mosaics. The model is implemented with a discrete event simulation and then used to investigate the performance of our system over a variety of parameters in our model. Our performance measure of choice is mean response time and by varying the composition of web pages through our categories, we find that our framework model is able to capture a wide range of conditions that serve as a basis for generating a variety of user request patterns. In addition, we are able to establish a set of parameters that can be used as base cases. One of the goals of this research is for the framework model to be general enough that the parameters can be varied such that it can serve as input for investigating other distributed applications that require the generation of user request access patterns.

基于Stacking融合模型的Web攻击检测方法

随着计算机技术与互联网技术的飞速发展,Web应用在人们的生产与生活中扮演着越来越重要的角色。但是在人们的日常生活与工作中带来了更多便捷的同时,却也带来了严重的安全隐患。在开发Web应用的过程中,大量不规范的新技术应用引入了很多的网站漏洞。攻击者可以利用Web应用开发过程中的漏洞发起攻击,当Web应用受到攻击时会造成严重的数据泄露和财产损失等安全问题,因此Web安全问题一直受到学术界和工业界的关注。超文本传输协议(HTTP)是一种在Web应用中广泛使用的应用层协议。随着HTTP协议的大量使用,在HTTP请求数据中包含了大量的实际入侵,针对HTTP请求数据进行Web攻击检测的研究也开始逐渐被研究人员所重视。本文提出了一种基于Stacking融合模型的Web攻击检测方法,针对每一条文本格式的HTTP请求数据,首先进行格式化处理得到既定的格式,结合使用Word2Vec方法和TextCNN模型将其转换成向量化表示形式;然后利用Stacking模型融合方法,将不同的子模型(使用配置不同尺寸过滤器的Text-CNN模型搭配不同的检测算法)进行融合搭建出Web攻击检测模型,与融合之前单独的子模型相比在准确率、召回率、F1值上都有所提升。本文所提出的Web攻击检测模型在公开数据集和真实环境数据上都取得了更加稳定的检测性能。

中国地震科学实验场三维断层模型Web展示原型系统

活动断层的三维结构和模型是地震危险性研究的基础参数和重要数据。随着对接近真实形态的活动断层三维模型的应用需求不断增加,对这类模型数据的共享及研究的需求也日益增加。数据共享课题的一个重要议题是如何构建基于Web的三维断层模型展示平台,提高数据共享水平和用户体验。中国地震科学实验场(川滇地区)三维断层模型Web展示原型系统①是基于Arc GIS 10.6企业版的Web App Builder工具构建的一个实验性系统。该系统实现了基于Web GIS的三维展示系统的基本功能,并成功测试了更适用于地震行业标准的用户交互方式、基本功能、场景数据迁移方案和三维场景设计方案。场景数据从三维断层建模平台到GIS平台的迁移,是实现基于Web GIS三维展示系统的基础。场景中展示的三维数据采用与二维数据标准一致且视觉上融合度高的可视化方案。实践结果表明,三维数据从建模平台迁出后,应结合数据可视化方案,在属性层面上与二维数据相融合,以保证二维和三维数据在视觉上较好地融合。

Testing and Evaluation for Web Usability Based on Extended Markov Chain Model

As the increasing popularity and complexity of Web applications and the emergence of their new characteristics, the testing and maintenance of large, complex Web applications are becoming more complex and difficult. Web applications generally contain lots of pages and are used by enormous users. Statistical testing is an effective way of ensuring their quality. Web usage can be accurately described by Markov chain which has been proved to be an ideal model for software statistical testing. The results of unit testing can be utilized in the latter stages, which is an important strategy for bottom-to-top integration testing, and the other improvement of extended Markov chain model (EMM) is to present the error type vector which is treated as a part of page node. this paper also proposes the algorithm for generating test cases of usage paths. Finally, optional usage reliability evaluation methods and an incremental usability regression testing model for testing and evaluation are presented. Key words statistical testing - evaluation for Web usability - extended Markov chain model (EMM) - Web log mining - reliability evaluation CLC number TP311. 5 Foundation item: Supported by the National Defence Research Project (No. 41315. 9. 2) and National Science and Technology Plan (2001BA102A04-02-03)Biography: MAO Cheng-ying (1978-), male, Ph.D. candidate, research direction: software testing. Research direction: advanced database system, software testing, component technology and data mining.

Model Checking-Based Testing of Web Applications

A formal model representing the navigation behavior of a Web application as the Kripke structure is proposed and an approach that applies model checking to test case generation is presented. The Object Relation Diagram as the object model is employed to describe the object structure of a Web application design and can be translated into the behavior model. A key problem of model checking-based test generation for a Web application is how to construct a set of trap properties that intend to cause the violations of model checking against the behavior model and output of counterexamples used to construct the test sequences. We give an algorithm that derives trap properties from the object model with respect to node and edge coverage criteria.

A colored Petri net-based model for web service composition

In this paper, a model based colored Petri net （CPN） to provide semantic support for web service composition is proposed, and the reliability and maintainability of composite services are improved. The composite constructs in the model are sequence, concurrent, choice, loop and replace. The web service is formally defined by a CPN. A closed composing algebra is defined to obtain a framework which enables declarative composition of web services. Availability, confidentiality, and integrity of composite service are analyzed within the framework of the model based CPN.

Enhancing Sustainable Development through Web Based 3D Smart City Model Using GIS and BIM. Case Study: Sheikh Hamad City

Smart sustainable city is that uses the technology to transform their core systems and optimize the exploitation of limited resources;it is a knowledge-based system that provides real-time insights to stakeholders. As a result of the challenges facing the cities of the Gaza Strip regarding population growth, lack of resources, increased demand for materials, the siege imposed on the Gaza Strip for more than twelve years, the smart city approach can contribute to mitigating these challenges and creating opportunities and solutions for many of these problems. Thus, this study aims to promote sustainable urban development through the adoption of smart city approaches using the city’s 3D representation and analysis capabilities to reflect and define the current situation and formulate a future vision using GIS and Building Information Modeling (BIM) considering Sheikh Hamad city as a case study. This involves developing a GIS web-based 3D model of the urban landscape of the city and creating a geometric descriptive database that includes the various elements of the city such as buildings, services and other facilities. The constructed database is to be automatically updated and can be used to facilitate documentation, transparency and help in decision-making process. The 3D smart city can also benefit stakeholders, government officials, private sectors as well as the city citizens. Therefore, urban services will be more efficient, and the cities of the Gaza Strip will be able to achieve sustainable development and competition in difficult economic, environmental and social conditions. This study recommends the use of BIM and GIS technologies in the transformation to a smart city concept as well as the rehabilitation of existing cadres to enable them to use those technologies to achieve the goal of improving the quality of life and facilitating the daily lives of people.

A Novel Lifecycle Model for Web-based Application Development in Small and Medium Enterprises

Software engineering＇s lifecycle models havc proven to be very important for traditional software development. However, can these models be applied to the development of Web-based applications as well？ In recent years, Web-based applications have become more and more complicated and a lot of efforts have been placed on introducing new technologies such as J2EE, PhP, and .NET, etc., which have been universally accepted as the development technologies for Web-based applications. However, there is no universally accepted process model for the development of Web-based applications. Moreover, shaping the process model for small medium-sized enterprises （SMEs）, which have limited resources, has been relatively neglected. Based on our previous work, this paper presents an expanded lifecycle process model for the development of Web-based applications in SMEs. It consists of three sets of processes, i.e., requirement processes, development processes, and evolution processes. Particularly, the post-delivery evolution processes are important to SMEs to develop and maintain quality web applications with limited resources and time.

Abstract Model Checking for Web Services

Web-services are highly distributed programs, and concurrent software is notoriously error-prone. Model checking is a powerful technique to find bugs in concurrent systems. However, the existing model checkers have no enough ability to support for the programming languages and communication mechanisms used for Web services. We propose to use Kripke structures as means of modeling Web service. This paper presents an automated way to extract formal models from programs implementing Web services using predicate abstraction for abstract model checking. The abstract models are checked by means of a model checker that implements automatic abstraction refinement. These results enable the verification of the applications that implement Web services.

A CONFERENCE CONTROL MODEL BETWEEN A WEB SERVER AND A TELECOM APPLICATION SERVER

The paper proposes a conference control model between a web server and a telecom application server,referred to as the Conference Directed Graph(CDG) ,and describes an asynchronous communication mechanism between them. The Corba Interface Definition Language(IDL) interfaces are defined,and a message sequence chart is illustrated. This web conference control model provides conference users with a new approach to manage and control a conference and the participants. The performance of the system prototype is analyzed and verified in the 863 project named "The Multi-media and Mobile Services Enabled Soft-switch System".

Analysis and Simulink Modeling of the Performance of Dynamic Web Server Using JSP and PHP

In recent years, web technology carried on growing and at same time, the number of internet users increased significantly in number. Today, a Web server is capable of processing millions of requests per day, but during the peak period may collapse and becomes critical causing unavailability of the services offered by the servers. That is why Web server performance is a topic of great interest to many researchers. In this paper, we evaluate experimentally the impact of JSP and PHP dynamic content technology: JSP and PHP with access to a database of performance data of Apache Web server. Using the “ApacheBench” performance measurement tool, the approach is to compare the performances of four different configurations of a Web server, such as: Apache Web server implementing JSP technology with access to PostgreSQL database, Apache using PHP technology with the PostgreSQL as database, Apache Web server using the JSP technology with access to MySQL database, finally Apache and PHP with DBMS MySQL. At the end of this article, we also present a Simulink model of Web server performance based on the simple M/M/1 queue. During the modeling, the MATLAB software was used.

Web software reliability modeling with random impulsive shocks

As the web-server based business is rapidly developed and popularized, how to evaluate and improve the reliability of web-servers has been extremely important. Although a large num- ber of software reliability growth models （SRGMs）, including those combined with multiple change-points （CPs）, have been available, these conventional SRGMs cannot be directly applied to web soft- ware reliability analysis because of the complex web operational profile. To characterize the web operational profile precisely, it should be realized that the workload of a web server is normally non-homogeneous and often observed with the pattern of random impulsive shocks. A web software reliability model with random im- pulsive shocks and its statistical analysis method are developed. In the proposed model, the web server workload is characterized by a geometric Brownian motion process. Based on a real data set from IIS server logs of ICRMS website （www.icrms.cn）, the proposed model is demonstrated to be powerful for estimating impulsive shocks and web software reliability.

Model checking web services choreography in process analysis toolkit

Web service （WS） is an emerging software technology, especially acting an important role in cloud computing. The WS choreography description language （WS-CDL） is the standard for modeling the observable behavior of WS composition across multiple participants from a global point of view. However, it lacks of a formal semantics and could easily lead to misunderstanding and different implementations. In this paper, the WS-CDL based specifications are formally extracted in a communicating sequential process supporting a formal approach to checking WS models. In addition, formalisms and model checking are explicitly illustrated through a simple but non-trivial example with the help of model checker process analysis toolkit （PAT）.

Web Service Description and Discovery Based on Semantic Model

A novel semantic model of Web service descrip tion and discovery was proposed through an extension for profile model of Web ontology language for services （OWL-S） in this paper. Similarity matching of Web services was implemented through computing weighted summation of semantic similarity value based on specific domain ontology and dynamical satisfy extent evaluation for quality of service （QoS）. Experiments show that the provided semantic matching model is efficient.

基于web技术的有限元模型和成果可视化方法研究

在水利水电工程设计及运行阶段,经常使用有限元分析方法进行结构受力变形分析。以往多数情况下都是高校或科研单位将有限元分析结果以固定图表的成果形式以研究报告的方式呈现给设计或运管单位,倘若边界条件或材料参数发生变化,设计或运管单位无法实时了解新的计算成果。随着Web技术的发展,使得将有限元模型和分析成果以可视化、交互式的方式向设计及运管人员进行实时呈现成为可能。借用基于WebGL技术封闭的Three.JS框架,实现了拱坝三维有限元网格模型及分析成果在用户浏览器上的可视化呈现,能够让用户通过交互式方式对有限元模型及分析成果进行动态浏览和查看,方便用户全面了解计算成果。该方法为数字孪生水利工程建设提供了计算分析成果在线查询技术,具有广泛的应用价值。

Generating test case specifications of web service composition using model checking

Model checking techniques have been widely used in verifying web service compositions to ensure the trustworthi- ness. However, little research has focused on testing web services. Based on the research of model checking techniques~ we propose a model checking based approach for testing web service composition which is described by using the web services choreography description language （WS-CDL）. According to worldwide web consortium （W3C） candidate recommendation, the WS-CDL specification provides a language for characterizing interactions between distinct web services using XML. Since the behaviors of web service composition are asynchronous, distributed, low-coupled and platform independent, we employ the guarded automata （GA） model for specifying the composition described in WS-CDL and using the simple promela interpreter （SPIN） model checker for detecting the collaborations of web services. Test cases can be transformed from counterexamples generated by SPIN using adequacy criteria. In this paper we apply the transition coverage criterion for generating counterex- amples. To illustrate our approach, we set ＂E-commerce service system＂ as an example for demonstrating how test cases can be generated using SPIN for compositions specified in WS-CDL.

基于Vue框架的医学3D模型展示测量分析的Web云平台

作为基于Vue的医学3D模型展示测量分析的Web云平台,平台整合了现代Web技术与医疗图像处理前沿技术,实现了医学3D模型数据的云端高效存储、高速传输与在线互动展示。该平台采用组件化、响应式的设计理念,结合Three.js等3D渲染库,能够流畅加载、渲染复杂医学3D模型,并提供精细化的模型测量、分析工具。平台支持多用户并发访问与权限管理,适用于跨地域的医疗团队协作,提高了医患沟通效率和医疗决策的科学性。

Statistical Models for Web Pages Usability

The usability of an interface is a fundamental issue to elucidate. Many researchers argued that many usability results and recommendations lack empirical and experimental data. In this research, the usability of the web pages is evaluated using several carefully selected statistical models. Universities web pages are chosen as subjects for this work for ease of comparison and ease of collecting data. A series of experiments has been conducted to investigate into the usability and design of the universities web pages. Prototype web pages have been developed according to the structured methodologies of web pages design and usability. Universities web pages were evaluated together with the prototype web pages using a questionnaire which was designed according to the Human Computer Interactions (HCI) heuristics. Nine (users) respondents’ variables and 14 web pages variables (items) were studied. Stringent statistical analysis was adopted to extract the required information to form the data acquired, and augmented interpretation of the statistical results was followed. The results showed that the analysis of variance (ANOVA) procedure showed there were significant differences among the universities web pages regarding most of the 23 items studied. Duncan Multiple Range Test (DMRT) showed that the prototype usability performed significantly better regarding most of the items. The correlation analysis showed significant positive and negative correlations between many items. The regression analysis revealed that the most significant factors (items) that contributed to the best model of the universities web pages design and usability were: multimedia in the web pages, the web pages icons (alone) organisation and design, and graphics attractiveness. The results showed some of the limitations of some heuristics used in conventional interface systems design and proposed some additional heuristics in web pages design and usability.

A Reference Model for the Analysis and Comparison of MDE Approaches for Web-Application Development

The emerging Model-Driven Engineering (MDE) paradigm advocates the use of models as first-class citizens in the software development process, while artifacts such as documentation and source-code can be quickly produced from those models by using automated transformations. Even though many MDE-oriented approaches, languages and tools have been developed in the recent past, there is no standard that concretely defines a specific sequence of steps to obtain a functional software system from a model. Thus, the existing approaches present numerous differences among themselves, because each one handles the problems inherent to software development in its own way. This paper presents and discusses a reference model for the comparative study of current MDE approaches in the scope of web-application development. This reference model focuses on relevant aspects such as modeling language scope (domain, business-logic, user-interface), usage of patterns, separation of concerns, model transformations, tool support, and deployment details like web-platform independence and traditional programming required. The ultimate goal of this paper is to determine the aspects that will be of greater importance in future web-oriented MDE languages.