Data Flow Aspects Research Articles

Enhancing IT Infrastructure with Fiber Optics: Revolutionizing Data Flow and Beyond

Fiber optics technology has emerged as a transformative solution in modern IT infrastructure, significantly enhancing data flow and other critical aspects of digital communication. This article explores the latest advancements in fiber optics and how they can be leveraged to improve IT infrastructure. By delving into the benefits of fiber optics, such as increased bandwidth, reduced latency, and improved security, this paper highlights how these technologies can revolutionize data transmission and overall IT operations.

Research on Data Security Detection Algorithm in IoT Based on K-means

The development of the Internet of Things has prominently expanded the perception of human beings, but ensuing security issues have attracted people's attention. From the perspective of the relatively weak sensor network in the Internet of Things. Proposed method is aiming at the characteristics of diversification and heterogeneity of collected data in sensor networks; the data set is clustered and analyzed from the aspects of network delay and data flow to extract data characteristics. Then, according to the characteristics of different types of network attacks, a hybrid detection method for network attacks is established. An efficient data intrusion detection algorithm based on K-means clustering is proposed. This paper proposes a network node control method based on traffic constraints to improve the security level of the network. Simulation experiments show that compared with traditional password-based intrusion detection methods; the proposed method has a higher detection level and is suitable for data security protection in the Internet of Things. This paper proposes an efficient intrusion detection method for applications with Internet of Things.

ReFSM: Reverse engineering from protocol packet traces to test generation by extended finite state machines

Protocol reverse engineering is helpful to automatically obtain the specifications of protocols that are useful for network management, network security systems and test case generation tools. To achieve better accuracy, these kinds of applications require good models that can capture not only the order of exchanging messages (control flow aspect) but also the data being transmitted (data flow aspect). However, current techniques only focus on inferring the control flow represented as a Finite State Machine (FSM) and without interpreting the data flow. The Extended Finite State Machine (EFSM), embedding memory in the states and data guard in the FSM transitions, is a method commonly used to represent the data flow. In this work, we propose ReFSM, a novel approach to infer the EFSMs of protocols from only network packet traces. The proposed method is evaluated by using datasets of real-world network traffic traces of four protocols: FTP, SMTP, BitTorrent and PPLive. Based on the results, the coverage, accuracy scores of correctness and behavior of inferred models are always higher than 90%. The precision and recall values of message type identification are, at least, well above 94% and 96%, respectively. The inferred EFSMs are close to the correct model derived from protocol specification.

Automatic Test Data Generation Using the Activity Diagram and Search-Based Technique

In software testing, generating test data is quite expensive and time-consuming. The manual generation of an appropriately large set of test data to satisfy a specified coverage criterion carries a high cost and requires significant human effort. Currently, test automation has come at the cost of low quality. In this paper, we are motivated to propose a model-based approach utilizing the activity diagram of the system under test as a test base, focusing on its data flow aspect. The technique is incorporated with a search-based optimization heuristic to fully automate the test data generation process and deliver test cases with more improved quality. Our experimental investigation used three open-source software systems to assess and compare the proposed technique with two alternative approaches. The experimental results indicate the improved fault-detection performance of the proposed technique, which was 11.1% better than DFAAD and 38.4% better than EvoSuite, although the techniques did not differ significantly in terms of statement and branch coverage. The proposed technique was able to detect more computation-related faults and tends to have better fault detection capability as the system complexity increases.

JUNO DAQ Readout and Event Building Research

The Jiangmen Underground Neutrino Observatory (JUNO) is a next-generation experiment designed to study the neutrino mass hierarchy, one of the open questions in particle physics. The entire experimental system includes the detector system, the electronics system, and the data acquisition (DAQ) system. Dataflow is the core of JUNO DAQ system. Readout system and event building (EB) system are two key aspects of dataflow. Based on the requirements analysis of JUNO DAQ, this paper proposes a data-flow schema of distributed network readout and second-level EB. Focusing on the performance requirements of JUNO DAQ, the performance of the readout and EB module, the number of readout processes and EB processes deployed on each node, the ratio of readout nodes and EB nodes, and scalability of the two modules are discussed in detail. The results of the research provide a reference for further optimization of the JUNO DAQ data-flow framework.

Is It “Trade?” Data Flows and the Digital Economy

This paper is a preliminary attempt to analyze information as a factor of production in international trade. It is a first attempt to get a handle on the direction and balance of information flows. We have obtained quantitative data about Web-related data flows between countries, and we explore how those flows are correlated to trade in goods . Using Telegeography data on “Server Location as a Percentage of Top Websites,” we found that 2/3 of all web traffic is transnational. More than half of the top 100 web sites in 9 of the world’s 13 sub-regions are hosted in the United States. Central Asia and Eastern Europe, for whom 37% and 41% of their most popular websites, respectively, are requested from the US. Even well-developed Western Europe makes almost half of its top 100 web site requests to US-based sites. For US users, on the other hand, only about 26 of the top 100 websites are hosted outside the country, and 20 of them are in Europe.Ironically, East Asia, which has a huge goods trade surplus with the developed economies, particularly with the US, has the largest negative balance in the relationship between incoming and outgoing Web requests. Indeed, we found a very strong negative correlation (-0.878) between web traffic balances and the balance of trade in goods across all subregions. Once these aspects of transnational data flows are quantified, the paper discusses the implications of these findings for policy, especially trade policy. It raises the question whether the goal of a free and open digital economy is best advanced by placing information exchanges in the trade paradigm and pushing for free trade, or by asserting a more general human right to free and open information exchanges across borders, which has social and political as well as economic consequences. These two approaches are not mutually exclusive, of course, but by making these distinctions we clarify the debate over international policy in the digital world.

International Trade, Internet Governance and the Shaping of the Digital Economy

The interface between trade and internet governance is one of the most complex policy challenges in the current-day digital economy. This paper highlights the following observations and findings on the delicate and complex relationship between international trade and the internet: (1) Recent PTAs such as the Trans-Pacific Partnership Agreement (‘TPP’) and the Japan-Mongolia Economic Partnership Agreement (‘Japan-Mongolia FTA’) contain legal provisions on cybersecurity, data protection, data localisation, consumer protection, net neutrality, spam control, and protection of online intellectual property, intended to facilitate electronic commerce and enable cross-border data flows. However, these provisions will also have a lasting impact on important aspects of internet regulation. Similar provisions are likely to appear in other ongoing trade deals such as the Trade in Services Agreement (‘TISA’) and the renegotiation of North American Free Trade Agreement (‘NAFTA’). (2) International trade law does not contain adequate tools to address all aspects of internet data flows because: (a) internet is not just an important platform for trade, but also a site for political, cultural and social engagement — the latter aspects largely relate to the domestic regulatory space of countries and fall outside the scope of international trade law; (b) trade lawyers and policy-makers have insufficient knowledge of the technical and policy aspects of the internet; and (c) the ideological divide between countries on issues including online censorship and surveillance, cybersecurity and privacy (which deeply impact cross-border data flows) cannot be resolved through international trade agreements. Yet, many issues related to internet policy are also central to trade in digital economy, and thereby, not entirely avoidable in international trade law. (3) Internet openness, security and trust are fundamental to the governance of internet data flows. Measures designed to enforce internet security and internet trust, when implemented in a well-reasoned and proportionate manner, do not act as impediments to internet openness — to the contrary, these measures play an essential role in facilitating efficient and secure data flows through the internet. Thus, issues of cybersecurity, privacy and data protection can not only act as barriers to electronic commerce, but also facilitate electronic commerce — this perspective necessitates a reorientation of legal provisions in trade agreements. (4) International trade institutions should explore both formal and informal means to engage with the internet policy community in course of dialogues and/or trade negotiations within the WTO as well as other plurilateral trade agreements, and in multistakeholder platforms such as the Internet Governance Forum. Further, international trade tribunals can rely on the technical and policy expertise of the internet community to resolve certain complex trade disputes in international trade law.

Formal verification of complex business processes based on high-level Petri nets

The Business Process Modeling Notation (BPMN) has been widely used as a tool for business process modeling. However, BPMN suffers from a lack of standard formal semantics. This weakness can lead to inconsistencies, ambiguities, and incompletenesses within the developed models. In this paper, we propose a formal semantics of BPMN using recursive ECATNets. Owing to this formalism, a large set of BPMN features such as cancellation, multiple instantiation of subprocesses and exception handling can be covered while taking into account the data flow aspect. The benefits and usefulness of this modelling are illustrated through three examples. Moreover, since recursive ECATNets semantics is defined in terms of conditional rewriting logic, one can use the Maude LTL model checker to verify several behavioral properties related to BPMN models. The work presented in this document has been automated through the development of a first prototype.

Automatic Transformation of UML System Models for Model-based Error Propagation Analysis of Mechatronic Systems

Abstract: Mechatronic systems consist of heterogeneous components: mechanical parts, hardware, and software. Appropriate models, which describe the mutual physical interaction on common Abstract levels, are required. UML is a widely accepted candidate for design and model-based analysis of the mechatronic systems. For the error propagation analysis on system level we have introduced a stochastic dual-graph error propagation model. This model captures control and data flow aspects of the system and allows the computation of various reliability metrics using discrete time Markov chain models. In our recent case-studies, UML Activity Diagrams have been used as baseline models. However, the transformation process was not fully automatic. This process is not so straightforward, despite the obvious structural similarities of the activity diagrams and our error propagation models. This article presents a new fully automatic method for the transformation of annotated activity diagrams. The transformation algorithm is described in detail with formal set-based mathematical notations. The article addresses both theoretical and technical sides of the problem. The method is demonstrated as a part of a complete analytical workflow in the frame of a mechatronic case study.

Data, Trade, and Growth

Cross-border data flows are a major aspect of today’s global economy. Moreover, the volume of cross-border data flows is growing at a rapid rate, with data flowing through terrestrial and submarine cables, and to a much lesser extent via satellites. According to TeleGeography, a consulting firm that keeps track of international data flows, demand for international bandwidth increased at a compound annual rate of 49 percent between 2008 and 2012. Cross-border data flows are also increasingly critical in trade negotiations. Cross-border data flows are one of the main subjects of the new round of trade negotiations announced by the United States Trade Representative, Ambassador Ron Kirk in January 2013. Similarly, the European Union is considering new data privacy regulations that would impact flows of data in and out of the EU. Ironically, statistics about the magnitude of cross-border data flows are scarce, despite their growing economic and political importance. The trade report from the Census Bureau and the Bureau of Economic Analysis contains some information about imports and exports of telecommunications services, but we show that these figures likely miss much of the increase in cross-border data traffic because of fundamental changes in the structure of global networks. Similarly, international agencies such as the ITU only collect fragmentary statistics on cross-border data flows, though they are putting more effort into estimating such figures. Moreover, we may not have the right conceptual framework for thinking about the economic impact of cross-border data flows. The usual categories of exports and imports don’t apply very well to cross-border data flows, since it’s not clear that an outflow of data from a country should count as an export. Indeed, long-established conventions treat outgoing international phone calls as imports, even though both the originating network and the receiving network play an equal role in the call. We will see below the assignment of outgoing international phone calls to the import category is essentially an artifact of regulation. This paper is intended as a preliminary exploration of the empirical, conceptual, and policy aspects of cross-border data flows. There are six sections. • An examination of how cross-border data flows are being reported — and not being reported — in the current trade statistics. • A typology of cross-border data flows. • An analysis of the magnitude of cross-border data flows, based on a comparison all internet/IP traffic. We find that for the United States, cross-border flows are roughly 16-25% of all U.S. data traffic, which is very significant. Cross-border data flows between Europe and the rest of the world equal roughly 13-16% of all European data traffic. These estimates, which should be treated as highly imprecise and tentative, suggest that the United States is more interconnected with the rest of the world than Europe. • An initial analysis of the economic benefits of cross-border data flows. In particular, we develop a framework for measuring the impact of data flows that cross borders without leaving a monetary footprint. • We explore the implications of latency as the equivalent of the “cost of shipping” for data. • Finally, we briefly examine the effects of policy on data, trade, and growth. An early draft of this paper was presented at a non-reviewed conference on “Measuring the Effects of Globalization” (Washington DC, February 28-March 1, 2013).

Managing data dependencies in service compositions

Composing services into service-based systems requires the design of coordination logic, which describes all service interactions realizing the composition. Coordination can be defined as the management of dependencies; in a services context we can discriminate between ‘control flow’ that manages sequence dependencies and ‘data flow’ for managing data dependencies. Current research fails to address the management of data dependencies in a systematic way and mostly treats it as subordinate to sequence dependencies. In this article a ‘data flow’ pattern language is presented that provides a systematic way of designing the data flow aspects of a coordination scenario, orthogonally to the way in which the control flow is designed. Starting from a set of fundamental and basic building blocks, each data dependency will yield a data flow design that takes a set of design criteria (e.g. loose coupling, data confidentiality, etc.) into account. The pattern language is evaluated in three ways. First, it is shown that every potential coordination scenario for managing a data dependency can be composed by the set of patterns. Second, the pattern language was applied in a real-life insurance case to show how it can guide the design of complex data flows. Third, the patterns were implemented in a tool that provides configurable model-to-code transformations for automatically generating BPEL coordination scenarios. In this tool both the data flow and control flow can be designed separately using different sets of patterns.

A schema aware ETL workflow generator

Extract, Transform and Load (ETL) processes organized as workflows play an important role in data warehousing. As ETL workflows are usually complex, various ETL facilities have been developed to address their control-flow process modeling and execution control. To evaluate the quality of ETL facilities, Synthetic ETL workflow test cases, consisting of control-flow and data-flow aspects are needed to check ETL facility functionalities at construction time and to validate the correctness and performance of ETL facilities at run time. Although there are some synthetic workflow and data set test case generation approaches existed in literatures, little work is done to consider both aspects at the same time specifically for ETL workflow generators. To address this issue, this paper proposes a schema aware ETL workflow generator with which users can characterize their ETL workflows by various parameters and get ETL workflow test cases with control-flow of ETL activities, complied schemas and associated recordsets. Our generator consists of three steps. First, with type and ratio of individual activities and their connection characteristic parameter specification, the generator will produce ETL activities and form ETL skeleton which determine how generated activities are cooperated with each other. Second, with schema transformation characteristic parameter specification, e.g. ranges of numbers of attributes, the generator will resolve attribute dependencies and refine input/output schemas with complied attributes and their data types. In the last step, recordsets are generated following cardinality specifications. ETL workflows in specific patterns are produced in the experiment in order to show the ability of our generator. Also experiments to generate thousands of ETL workflow test cases in seconds have been done to verify the usability of the generator.

Visually specifying compliance rules and explaining their violations for business processes

A business process is a set of steps designed to be executed in a certain order to achieve a business value. Such processes are often driven by and documented using process models. Nowadays, process models are also applied to drive process execution. Thus, correctness of business process models is a must. Much of the work has been devoted to check general, domain-independent correctness criteria, such as soundness. However, business processes must also adhere to and show compliance with various regulations and constraints, the so-called compliance requirements. These are domain-dependent requirements. In many situations, verifying compliance on a model level is of great value, since violations can be resolved in an early stage prior to execution. However, this calls for using formal verification techniques, e.g., model checking, that are too complex for business experts to apply. In this paper, we utilize a visual language, BPMN-Q, to express compliance requirements visually in a way similar to that used by business experts to build process models. Still, using a pattern based approach, each BPMN-Q graph has a formal temporal logic expression in computational tree logic (CTL). Moreover, the user is able to express constraints, i.e., compliance rules, regarding control flow and data flow aspects. In order to provide valuable feedback to a user in case of violations, we depend on temporal logic querying approaches as well as BPMN-Q to visually highlight paths in a process model whose execution causes violations.

A process-view approach for cross-organizational workflows management

Workflow management for cross-organizational business processes presents a significant challenge recently. The development and implementation of new methodologies and technologies are imperative to tackle this challenge. The process-view approach provides a promising way to facilitate cross-organizational workflows management, especially when it is combined with powerful workflow modeling methods. With the assumption that workflow modeling methods in cooperative organizations are interoperable, a process-view and timed colored Petri net (TCPN) combined approach is proposed to manage cross-organizational workflows, including the formal definition, the mapping from TCPN workflow models to process-view workflow models in which the aspects of control flow and data flow are considered together, and the collaborative execution mechanisms of cross-organizational workflow instances. A hybrid P2P based decentralized workflow management system (WMS) combined with the process-view approach is proposed and built, which is placed on the top of the open JXTA platform and provides a flexible and scalable architecture for cross-organizational workflows management. At last, the cross-organizational workflows management for the distributed development of a circular saw has been used as a test case for system validation.

Conceptual-level workflow modeling of scientific experiments using NMR as a case study.

BackgroundScientific workflows improve the process of scientific experiments by making computations explicit, underscoring data flow, and emphasizing the participation of humans in the process when intuition and human reasoning are required. Workflows for experiments also highlight transitions among experimental phases, allowing intermediate results to be verified and supporting the proper handling of semantic mismatches and different file formats among the various tools used in the scientific process. Thus, scientific workflows are important for the modeling and subsequent capture of bioinformatics-related data. While much research has been conducted on the implementation of scientific workflows, the initial process of actually designing and generating the workflow at the conceptual level has received little consideration.ResultsWe propose a structured process to capture scientific workflows at the conceptual level that allows workflows to be documented efficiently, results in concise models of the workflow and more-correct workflow implementations, and provides insight into the scientific process itself. The approach uses three modeling techniques to model the structural, data flow, and control flow aspects of the workflow. The domain of biomolecular structure determination using Nuclear Magnetic Resonance spectroscopy is used to demonstrate the process. Specifically, we show the application of the approach to capture the workflow for the process of conducting biomolecular analysis using Nuclear Magnetic Resonance (NMR) spectroscopy.ConclusionUsing the approach, we were able to accurately document, in a short amount of time, numerous steps in the process of conducting an experiment using NMR spectroscopy. The resulting models are correct and precise, as outside validation of the models identified only minor omissions in the models. In addition, the models provide an accurate visual description of the control flow for conducting biomolecular analysis using NMR spectroscopy experiment.

FORMAL METHOD FOR AUTOMATED TRANSFORMATION OF LOTOS SPECIFICATIONS TO ESTELLE SPECIFICATIONS

ISO and IEC have jointly developed two Formal Description Techniques (FDTs) for specifying distributed real time systems such as computer/telecommunications protocols. These are Lotos and Estelle. In this paper, a formal method for automated transformation of a Lotos specification to an Estelle specification is presented. The method is applicable to various Lotos specification styles and to various communications protocols of ISO OSI layers. Our method has applications in conformance testing of such systems and building common semantic model for the various FDTs. In this paper, we develop an algorithm for constructing a 'Data Oriented'-Restricted Behavior Tree T that represent both the control flow aspects and the data flow aspects of the system. Then, we develop an algorithm for constructing the Estelle specifications from T. A minimization rule is also developed to optimize the size of the Estelle specification by reducing both the number of states and the number of transitions.

Formal method for automated testing data flow aspects of communications protocols, software, and systems specified in Lotos

In this paper, we discuss the testing of data flow aspects of communications protocols and distributed systems specified in Lotos; the ISO Formal Description Technique (FDT). We also develop a method for automated derivation of sequences to conformance test data flow aspects of a system specified in Lotos. This has applications for communications protocols, software, and distributed real time systems in general. We generalize the testing method, with best known coverage, developed for Extended Finite State Machines (EFSMs) to the algebraic FDT Lotos. The method firstly constructs a Data-Oriented Restricted Behavior Tree that represents the behavior of the given specification. An algorithm for the automated construction of T is developed in this paper. Then, the testing sequences are driven.

The second level trigger of the ATLAS experiment at CERN's LHC

The ATLAS trigger reduces the rate of interesting events to be recorded for off-line analysis in three successive levels from 40 MHz to /spl sim/100 kHz, /spl sim/2 kHz and /spl sim/200 Hz. The high level triggers and data acquisition system are designed to profit from commodity computing and networking components to achieve the required performance. In this paper, we discuss data flow aspects of the design of the second level trigger (LVL2) and present results of performance measurements.

Context independent unique state identification sequences for testing communication protocols modelled as extended finite state machines

A number of test sequence generation methods proposed for communication protocols represented as Extended Finite State Machines (EFSMs) use state identification sequences for checking the states. However, neither a formal definition nor a method of computation of these sequences for an EFSM state is known. In this paper, we first define a new type of state identification sequence, called Context Independent Unique Sequence (CIUS) and present an algorithm for computing it. To demonstrate the usefulness of these sequences, we then briefly describe a unified method based on CIUSs for automatically generating executable test cases for both control flow and data flow aspects of an EFSM. In control flow testing, CIUSs are very useful in confirming the tail states of the transitions. In data flow testing, CIUSs improve the observability of the test cases for the def-use associations of different variables used in the EFSM. Unlike general state identification sequences, the use of CIUSs does not increase the complexity of the already intractable feasibility testing problem in test case generation. Moreover, the feasibility problem encountered in both the CIUS computation and the test case generation methods is amenable to an incremental solution. We demonstrate this by presenting a method to solve a particular case of this problem in which the variables are of only integer, real or Boolean type and the predicates are linear.

Dynamic data flow analysis for Java programs

A large portion of high-level computer programs consists of data declaration. Thus, an increased focus on testing the data flow aspects of programs should be considered. In this paper, we consider testing the data flow in Java programs dynamically. Data flow analysis has been applied for testing procedural and some object-oriented programs. We have extended the dynamic data flow analysis technique to test Java programs and show how it can be applied to detect data flow anomalies.