Proxy Architecture Research Articles

SIFR annotator: ontology-based semantic annotation of French biomedical text and clinical notes

BackgroundDespite a wide adoption of English in science, a significant amount of biomedical data are produced in other languages, such as French. Yet a majority of natural language processing or semantic tools as well as domain terminologies or ontologies are only available in English, and cannot be readily applied to other languages, due to fundamental linguistic differences. However, semantic resources are required to design semantic indexes and transform biomedical (text)data into knowledge for better information mining and retrieval.ResultsWe present the SIFR Annotator (http://bioportal.lirmm.fr/annotator), a publicly accessible ontology-based annotation web service to process biomedical text data in French. The service, developed during the Semantic Indexing of French Biomedical Data Resources (2013–2019) project is included in the SIFR BioPortal, an open platform to host French biomedical ontologies and terminologies based on the technology developed by the US National Center for Biomedical Ontology. The portal facilitates use and fostering of ontologies by offering a set of services –search, mappings, metadata, versioning, visualization, recommendation– including for annotation purposes. We introduce the adaptations and improvements made in applying the technology to French as well as a number of language independent additional features –implemented by means of a proxy architecture– in particular annotation scoring and clinical context detection. We evaluate the performance of the SIFR Annotator on different biomedical data, using available French corpora –Quaero (titles from French MEDLINE abstracts and EMEA drug labels) and CépiDC (ICD-10 coding of death certificates)– and discuss our results with respect to the CLEF eHealth information extraction tasks.ConclusionsWe show the web service performs comparably to other knowledge-based annotation approaches in recognizing entities in biomedical text and reach state-of-the-art levels in clinical context detection (negation, experiencer, temporality). Additionally, the SIFR Annotator is the first openly web accessible tool to annotate and contextualize French biomedical text with ontology concepts leveraging a dictionary currently made of 28 terminologies and ontologies and 333 K concepts. The code is openly available, and we also provide a Docker packaging for easy local deployment to process sensitive (e.g., clinical) data in-house (https://github.com/sifrproject).

Photonic-Frame-Based TCP proxy architecture in optically interconnected data center networks

Optical switching is a good candidate for achieving the key requirements of high scalability, low latency and low power consumption in future large-scale data center networks (DCNs). However, circuit-based optical switching has a disadvantage of a long reconfiguration time. Packet-based optical switching also faces challenges such as the complexity of optical header processing and the difficulty of buffering in optical switches to resolve contention. To address these problems, we present a packet-switched optical network architecture design with a photonic frame wrapper that can generate variable-size photonic frames for optically interconnected intra-DCN. The proposed architecture forms hybrid DCN architecture consisting of a flattened optical switch layer for the data path and a conventional electrical switch layer for the control path. The photonic frame wrapper can increase bandwidth utilization by minimizing guard-time insertion in the optical switch domain. We also introduce a photonic frame wrapper with proxy solution to fully exploit the gain of the proposed architecture even in inter-DCN communication with long delays, which is compliant with standard TCP instances at end nodes. In intra-DCN, the average queuing delay is analyzed to find the efficient combinations between the guard time and time-slot length for the variable-sized photonic frame. We also analyzed the bandwidth overhead of guard time, to show it is comparable to that of Ethernet based DCN. In inter-DCN, the proxy solution demonstrates a noticeable TCP performance enhancement compared with the photonic frame wrapper in terms of bandwidth efficiency and end-to-end delay by theoretical and OPNET simulation analyses.

Enhanced functionalities for annotating and indexing clinical text with the NCBO Annotator.

SummarySecond use of clinical data commonly involves annotating biomedical text with terminologies and ontologies. The National Center for Biomedical Ontology Annotator is a frequently used annotation service, originally designed for biomedical data, but not very suitable for clinical text annotation. In order to add new functionalities to the NCBO Annotator without hosting or modifying the original Web service, we have designed a proxy architecture that enables seamless extensions by pre-processing of the input text and parameters, and post processing of the annotations. We have then implemented enhanced functionalities for annotating and indexing free text such as: scoring, detection of context (negation, experiencer, temporality), new output formats and coarse-grained concept recognition (with UMLS Semantic Groups). In this paper, we present the NCBO Annotator+, a Web service which incorporates these new functionalities as well as a small set of evaluation results for concept recognition and clinical context detection on two standard evaluation tasks (Clef eHealth 2017, SemEval 2014).Availability and implementationThe Annotator+ has been successfully integrated into the SIFR BioPortal platform—an implementation of NCBO BioPortal for French biomedical terminologies and ontologies—to annotate English text. A Web user interface is available for testing and ontology selection (http://bioportal.lirmm.fr/ncbo_annotatorplus); however the Annotator+ is meant to be used through the Web service application programming interface (http://services.bioportal.lirmm.fr/ncbo_annotatorplus). The code is openly available, and we also provide a Docker packaging to enable easy local deployment to process sensitive (e.g. clinical) data in-house (https://github.com/sifrproject).Supplementary information Supplementary data are available at Bioinformatics online.

Transparent RAN Sharing of 5G Small Cells and Macrocells

To cope with the growth of mobile data traffic in 5G systems, telecom operators have to set up more small cells and macrocells in the same area. However, because of space limitations, it is difficult for each operator to do so, and RAN sharing would thus become mandatory for 5G systems. In this work, RANP is proposed, which will achieve transparent RAN sharing by setting up RANP between a base station to be shared and multiple core networks. Over and above the general one-level proxy architecture, an extended two-level architecture is proposed that will share both small cells and macrocells. According to our emulation results, additional packet processing time of a RANP is about 2 ms, 3.8 percent of the total end-to-end latency. Its impact on throughput is about 3 percent and can be regarded as irrelevant.

Anonymous authentication scheme based on identity-based proxy group signature for wireless mesh network

Access security is the key obstacle of the rapid popularization of wireless mesh network (WMN). We suggest the proxy group signature scheme based on identity in this paper. This scheme is combined with proxy group signature and identity-based group signature, based on designated hierarchical proxy architecture for WMN. An anonymous mutual authentication scheme is thus achieved, which not only simplifies the complex management of PKI but also guarantees anonymous authentication and owns high handover authentication efficiency. Performance and security analysis show that the scheme in this paper is efficient and resilient to a series of security and anonymity attacks.

Assessing the Potential for Saving Energy by Impersonating Idle Networked Devices

The idea of proxying network connectivity has been proposed as an efficient mechanism to maintain network presence on behalf of idle devices, so that they can “sleep.” The concept has been around for many years; alternative architectural solutions have been proposed to implement it, which lead to different considerations about capability, effectiveness and energy efficiency. However, there is neither a clear understanding of the potential for energy saving nor a detailed performance comparison among the different proxy architectures. In this paper, we estimate the potential energy saving achievable by different architectural solutions for proxying network connectivity. Our work considers the tradeoff between the saving achievable by putting idle devices to sleep and the additional power consumption to run the proxy. Our analysis encompasses a broad range of alternatives, taking into consideration both implementations already available in the market and prototypes built for research purposes. We remark that the main value of our work is the estimation under realistic conditions, taking into consideration power measurements, usage profiles, and proxying capabilities.

A Mobile Proxy Architecture for Video Services Over High-Speed Rail Environments in LTE-A Networks

With the rapid developments in wireless communication technology, people access Internet applications anytime and anywhere. Recently, academics and industry researchers have been paying increasing attention to the video streaming services over high-speed rail environments. For providing the quality of service of video streaming, we present a novel mobile proxy architecture for improving the system performance over high-speed trains in Long Term Evolution–Advanced networks. The mobile proxy not only saves the wireless bandwidth consumption between the base station and the high-speed train but also reduces the starting delay time of the video. Moreover, we propose a score-based replacement scheme in the memory management of the proxy server based on the feature of the video. Our simulation results demonstrate that the proposed scheme provides a better performance than other existing cache management schemes.

P2PRPIPS: A P2P and Reverse Proxy Based Web Intrusion Protection System

In order to protect web sites with various program languages and high throughput efficiently, a web Intrusion Protection System (IPS) based on P2P and reverse proxy architecture was designed and implemented. The P2P based web intrusion protection system has multi web firewall nodes and nodes with same program cooperate with each other under P2P architecture. Some nodes work as net flow allocator and some work as detector and they can convert to each other according to the requirements dynamically. The WAF program has the characteristics of session keeping and load balancing and it can detect messages by using expert library and many plug-in components. The technology of reverse proxy is used for response the web request. Experiments show that the system can effectively prevent attacks form application layer. It is proved more efficient and stable than single node.

Seamless Video Session Handoff between WLANs

Handoff in a distributed IEEE 802.11 Wireless LAN network is a source of significant amount of problems on the video transmission environment. The visual quality of video streaming applications is lowered when stations are in handoff status. In this paper, we introduce an architecture of a session proxy (SP), which tries to preserve the quality of the streaming video upon each handoff between access points. We have evaluated thresholds of RSSI and Loss Frame Rate (LFR) for deciding the moment when the handoff process shall begin. Our solution performance was evaluated in a testbed implementation for MPEG-4 video on demand with one video server (VLS) and two FreeBSD-based access points supporting Mobile IP, DHCP Server and IAPP approach.

Distributed collaborative system of product designing and manufacturing based on grid services

A distributed collaborative system based on grid services is proposed in this paper to support collaborative designing and manufacturing of products. The base of this system is an abstract model of collaborative designing and manufacturing. Resources are encapsulated into service objects and then the integration and sharing of these distributed heterogeneous resources are realised by using service proxy and open grid services architecture (OGSA). Services and interfaces of resources are described by extensible markup language (XML). The publishing and discovery of services are realised by utilising standardisation rule and similar vector matching technology. Lastly, the practicality of this system is validated by its application in the designing and manufacturing process of a product.

Versatile Transcoding Proxy for Internet Content Adaptation

Recent technology advances in multimedia communication have ushered in a new era of personal communication. Users can ubiquitously access the Internet via various mobile devices. For the mobile devices featured with lower bandwidth network connectivity, transcoding can be used to reduce the object size by lowering the quality of a multimedia object. In view of the monolithic transcoders which only provide transcoding services and have limited performances due to the unknown data types and protocols in the prior research, we propose the architecture of versatile transcoding proxy (VTP). Based on the concept of the agent system, the VTP architecture can accept and execute the transcoding preference script provided by the client or the server to transform the corresponding data or protocol according to the user's specification. In order to enhance the effectiveness of the VTP architecture, we adopt the concept of dynamic cache categories and propose the scheme maximum profit replacement with dynamic cache categories (DCC-MPR). Based on the weighted transcoding graph, scheme DCC-MPR performs cache replacement according to the content in the caching candidate set, which is generated by the concept of dynamic programming. The experimental results show that the proposed architecture VTP and the corresponding scheme DCC-MPR have better performances in many aspects compared to the conventional transcoding proxy systems.

A QoS-Aware and Energy-Conserving Transcoding Proxy Using On-Demand Data Broadcasting

Most research works in transcoding proxies in mobile computing environments are on the basis of the traditional client-server architecture and do not employ the data broadcast technique. In addition, the issues of QoS provision and energy conservation are also not addressed in the prior studies. In view of this, we design in this paper a QoS-aware and energy-conserving transcoding proxy by utilizing the on-demand broadcasting technique. We first propose a QoS-aware and energy-conserving transcoding proxy architecture, abbreviated as QETP, and model it as a queuing network consisting of three queues. By analyzing the queuing network, three lemmas are derived to estimate the load of these queues. We then propose a version decision policy and a service admission control scheme to provide QoS in QETP. The derived lemmas are used to guide the execution of the proposed version decision policy and service admission control scheme to achieve the given QoS requirement. In addition, we also propose a data indexing method to reduce the power consumption of clients. To measure the performance of the proposed architecture, three experiments are conducted. Experimental results show that the average access time reduction of the proposed scheme over the traditional client-server architecture ranges from 45 percent to 75 percent. Experimental results also show that the proposed scheme is more scalable than the traditional client-server architecture and is able to effectively control the system load to attain the given QoS requirements. In addition, the proposed scheme is able to greatly reduce the average tuning time of clients at the cost of a slight increase (around 5 percent in our experiments) in average access time.

IDN server proxy architecture for Internationalized Domain Name resolution and experiences with providing Web services

The composition of traditional domain names are restricted to ASCII letters, digits, and hyphens (abbreviated as LDH). This makes it difficult for many to use their native language to name and access their Internet hosts. The IETF IDN (Internationalized Domain Name) Working Group proposes a mechanism, IDNA (Internationalizing Domain Names in Applications), for internationalized access to multilingual domain names. The proposal uses a preparation process that converts a Unicode IDN into an ACE (ASCII Compatible Encoding) string that uses only LDH. Thus, applications can look up the ACE string by using the existing DNS infrastructure. However, some of the domain name strings embedded in multilingual content do not have any charset tag so they cannot appropriately be converted into ACE strings. We noticed that many Internet applications allow users to use non-ASCII domain names. We were motivated to design an architecture for IDN resolution as well as to minimize the cost of modifying legacy Internet applications. We specifically focus on designing an IDN server proxy, which is located on the domain name server side, to handle domain names in multiple encodings. In this article, we study several architecture design issues including detection of charset encoding, routing of non-ACE IDN lookup requests, and so on.With respect to these design issues, we present an IDN server proxy architecture which stores ACE IDNs in domain name servers. Note that traditional domain name servers can be used without modification. An IDN server proxy, called Octopus, is employed on the domain name server side. Octopus converts a non-ACE IDN string into ACE upon receiving an IDN lookup request from remote users or autonomous systems. The ACE string is then forwarded to backend domain name servers (where the traditional domain names and ACE IDNs are stored) for further processing. This allows Internet users to access IDNs without having to upgrade their software.Based on the design and implementation of Octopus, we deployed a CDN (Chinese domain name) trial in July 2002. In this article, we present the results of testing Octopus IDN lookup functions as well as our experiences in providing CDN Web services. Several types of errors can occur if applications are unable to handle IDNs adequately. For example, a Web browser may erroneously parse an IDN within a URL. Many legacy Web servers are unable to process the IDN of a virtual host. Web application servers may have trouble completing some actions such as redirecting Web pages to alternative Web pages. Our studies help service providers understand potential problems when non-ASCII domain names are used and the best common practice at this stage. As well, the experiences give some guidance for software developers to develop IDNA-compliant Internet applications.

A Proxy Architecture to Enhance the Performance of WAP 2.0 by Data Compression

This paper presents a novel proxy architecture for wireless application protocol (WAP) 2.0 employing an advanced data compression scheme. Though optional in WAP 2.0, a proxy can isolate the wireless from the wired domain to prevent error propagations and to eliminate wireless session delays (WSD) by enabling long-lived connections between the proxy and wireless terminals. The proposed data compression scheme combines content compression together with robust header compression (ROHC), which minimizes the air-interface traffic data, thus significantly reduces the wireless access time. By using the content compression at the transport layer, it also enables TLS tunneling, which overcomes the end-to-end security problem in WAP 1.x. Performance evaluations show that while WAP 1.x is optimized for narrowband wireless channels, WAP 2.0 utilizing TCP/IP outperforms WAP 1.x over wideband wireless channels even without compression. The proposed data compression scheme reduces the wireless access time of WAP 2.0 by over 45% in CDMA2000 1XRTT channels, and in low-speed IS-95 channels, substantially reduces access time to give comparable performance to WAP 1.x. The performance enhancement is mainly contributed by the reply content compression, with ROHC offering further enhancements.

PTC: Proxies that Transcode and Cache in Heterogeneous Web Client Environments

Advances in computing and communication technologies have resulted in a wide variety of networked mobile devices that access data over the Internet. We argue that servers by themselves may not be able to handle this diversity in client characteristics and intermediate proxies should be employed to handle the mismatch between server-supplied data and client capabilities. Since existing proxies are primarily designed to handle traditional wired hosts, such proxy architectures will need to be enhanced to handle mobile devices. We propose such an enhanced proxy architecture that is capable of handling the heterogeneity in client needs - specifically the variations in client bandwidth and display capabilities. Our architecture combines transcoding (which is used to match the fidelity of the requested object to client capabilities) and caching (which is used to reduce the latency for accessing popular objects). Our proxies can intelligently adapt to prevailing system conditions using learning techniques to intelligently decide whether to transcode locally or fetch an appropriate version from the server. Our experimental results indicate that such strategies produce significant improvements in client response times. Further we find that even simple learning techniques can lead to significant performance improvements.

Fine-grained device management in an interactive media server

The use of interactive media has already gained considerable popularity. Interactivity gives viewers VCR controls like slow-motion, pause, fast-forward, and instant replay. However, traditional server-based or client-based approaches for supporting interactivity either consume too much network bandwidth or require large client buffering; and hence they are economically unattractive. We propose the architecture and design of an interactive media proxy (IMP) server that transforms noninteractive broadcast or multicast streams into interactive ones for servicing a large number of end users. For IMP to work cost-effectively, it must carefully manage its storage devices, which are needed for caching voluminous media data. In this regard, we propose a fine-grained device management strategy consisting of three complementary components: disk profiler, data placement, and IO scheduler. Through quantitative analysis and experiments, we show that these fine-grained strategies considerably improve device throughput under various workload scenarios.

A proxy architecture for collaborative media streaming

A proxy architecture for collaborative media streaming

MSOCKS+: an architecture for transport layer mobility

Mobile nodes of the future will be equipped with multiple network interfaces to take advantage of overlay networks, yet no current mobility systems provide full support for the simultaneous use of multiple interfaces. The need for such support arises when multiple connectivity options are available with different cost, coverage, latency and bandwidth characteristics, and applications want their data to flow over the interface that best matches the characteristics of the data. In this paper we introduce and analyze an architecture called Transport Layer Mobility that allows mobile nodes to not only change their point of attachment to the Internet within a corporate domain, but also to control which network interfaces are used for the different kinds of data leaving from and arriving at the mobile node. We implement our transport layer mobility scheme using a split–connection proxy architecture and a new technique called TCP Splice that gives split–connection proxy systems the same end-to-end semantics as normal TCP connections. We introduce the architecture, present its system aspects, investigate its performance and present its reliability properties. The analytical aspects of the protocol, in particular its pseudo-code, its properties and its validation are given in a related Technical Report.

A composable framework for secure multi-modal access to internet services from Post-PC devices

The Post-PC revolution is bringing information access to a wide range of devices beyond the desktop, such as public kiosks, and mobile devices like cellular telephones, PDAs, and voice based vehicle telematics. However, existing deployed Internet services are geared toward the secure rich interface of private desktop computers. We propose the use of an infrastructure-based secure proxy architecture to bridge the gap between the capabilities of Post-PC devices and the requirements of Internet services. By combining generic content and security transformation functions with service-specific rules, the architecture decouples device capabilities from service requirements and simplifies the addition of new devices and services. Security and protocol specifics are abstracted into reusable components. Additionally, the architecture offers the novel ability to deal with untrusted public Internet access points by providing fine-grain control over the content and functionality exposed to the end device, as well as support for using trusted and untrusted devices in tandem. Adding support for a deployed Internet service requires a few hundred lines of scraping scripts. Similarly, adding support for a new device requires a few hundred lines of stylesheets for the device format. The average latency added by proxy transformations is around three seconds in our unoptimized Java implementation.

WebAssist: a user profile specific information retrieval assistant

Despite the ever increasing information available on the Internet today, finding accurate information for a specific topic becomes more and more difficult. This paper describes the concept of a proxy based information classification and filtering utility, named WebAssist. On the behalf of users a private view of the WWW is generated based on a previously determined profile. This profile is created by monitoring the user (and group) activities when browsing WWW pages. Additional features are integrated to allow for easy interoperability in workgroups with similar project interests, maintain personal and common hotlists with automatic modification checks and a sophisticated search engine front-end. The proxy architecture allows easy configurability using standard Web browsers and eliminates the necessity to install additional platform specific software.