基于MSRP的离线消息服务系统的研究与设计

即时消息作为一种新的通信方式,业务扩展范围非常广泛。提出了一种基于消息会话中继协议,即MSRP协议的通信服务器集群的实现框架,能够支持SIP系统中的离线消息业务。首先针对MSRP协议工作在会话模式下的特性,提出了服务系统的整体设计思想,并研究分析了转储和推送离线消息的信令流程。然后提出了通信服务器集群的实现方案和集群内部的通信框架。服务系统能够在SIP软终端的配合下处理基于MSRP的离线消息业务。     

一种面向频道的消息服务模型

针对信息系统之间数据交换和信息共享的主要方式——消息服务应用的日益增多和服务信息的不断多样化,提出一种面向频道的消息服务模型,在对消息传输通道的封装基础上,采用一种消息的逻辑组织单元——频道来动态进行消息服务的注册和管理,在频道中可以管理消息服务分类,并能添加消息融合,实验结果证明其可以提高消息服务的灵活性和消息传输的性能。     

Instant messaging puts on a business suit

Despite the many users, the three big consumer instant messaging (IM) companies don't make money directly from instant messaging because the service is free. They have thus been looking for a way to sell enhanced IM services to companies. Businesses want more from IM than they get from the consumer versions they've been using. For example, consumer systems typically don't offer security, message archiving, auditing, or ways to control user access.     

A visual programming language for XML manipulation

XML data flow has reached beyond the world of computer science and has spread to other areas such as data communication, e-commerce and instant messaging. Therefore, manipulating this data by non-expert programmers is becoming imperative and has emerged two alternatives. On one hand, Mashups have emerged a few years ago, providing users with visual tools for web data manipulation but not necessarily XML specific. Mashups have been leaning towards functional composition but no formal definitions have yet been defined. On the other hand, visual languages for XML have been emerging since the standardization of XML, and mostly relying on querying XML data for extraction or structure transformations. These languages are mainly based on existing textual XML languages, they have limited expressiveness and do not provide non-expert programmers with means to manipulate XML data. In this paper, we define a generic visual language called XCDL based on Colored Petri Nets allowing non-expert programmers to compose manipulation operations. The XML manipulations range from simple data selection/projection to data modification (insertion, removal, obfuscation, etc.). The language is oriented to deal with XML data (XML documents and fragments), providing users with means to compose XML oriented operations. The language core syntax is presented here along with an implemented prototype based on it.     

Extending the reach of business processes

A business process is a systematic set of activities by which an enterprise conducts its affairs. Various technologies-including pagers, cell phones, pocket PCs, instant messaging (IM), and the short message service (SMS)-have emerged that people can use to communicate even when they are on the move or far away. Many such devices support synchronous communication as well as proactively "pushing" messages to users. However, these devices have no mechanism to control or structure the information that users are exchanging, and they arc not integrated with business processes based on workplaces. To address these problems, we have designed and implemented PerCollab, a middleware system that facilitates structured collaboration between various communication devices for business processes and pushes tasks to users.     

Red5在Jabber服务器视频通信中的应用

Jabber是一种针对即时消息和现场服务的开放协议,可以和多种即时通信对接。Red5是一个采用Java开发开源的Flash流媒体服务器,具有强大的多媒体功能。本文正是结合两者的优点,提出了一种即时、高效的视频通信解决方案。     

“What do they snapchat about?” Patterns of use in time-limited instant messaging service

The use of Snapchat – a time-limited instant messaging service – has been rapidly rising amongst adolescents. However, the exact nature of Snapchat use remains difficult to examine due to the self-destructive nature of content sent and received via this service. We report an online survey conducted with the use of a memory sampling method to enquire about the specific details of the very last image or video each participant sent and received via Snapchat. We found that users mainly share ‘selfies’, typically embed text and ‘doodles’ with photos they share, use it mostly at home, and primarily for communication with close friends and family as an ‘easier and funnier’ alternative to other instant messaging services. We also found that high intensity of Snapchat use was more associated with bonding rather than bridging social capital. We discuss those findings in the context of existing studies on the use of instant messaging services and social networking sites.     

Towards an open protocol for secure online presence notification

It is important to know the presence of other concurrently online users before real-time communication can be established with them. While many instant messaging (IM) systems are available, there is no standard protocol for online presence notification due to the proprietary nature of such systems. These systems generally have many security weaknesses such as anonymous messaging, message spoofing, account hijacking and authorization overriding because they depend heavily on client-side operations. This paper proposes an open protocol for online presence notification that also provides negotiation support for real-time communication services. The open nature of the protocol promotes interoperability, but demands higher levels of security than proprietary ones. The separation of instant messaging from online presence notification also distinguishes this open protocol from others. Furthermore, a relatively secure presence notification system based on the proposed protocol has been implemented with its performance evaluated.     

Spam filtering framework for multimodal mobile communication based on dendritic cell algorithm

With the continual growth of mobile devices, they become a universal portable platform for effective business and personal communication. They enable a plethora of textual communication modes including electronic mails, instant messaging, and short messaging services. A downside of such great technology is the alarming rate of spam messages that are not only annoying to end-users but raises security concerns as well. This paper presents an intelligent framework for filtering multimodal textual communication including emails and short messages. We explore a novel methodology for information fusion inspired by the human immune system and hybrid approaches of machines learning. We study a number of methods to extract and select more relevant features to reduce the complexity of the proposed model to suite mobile applications while preserving good performance. The proposed framework is intensively evaluated on a number of benchmark datasets with remarkable results achieved.     

企业级即时通讯技术及其应用

基于网络的协同工作是办公自动化的高层次应用,也是其发展的趋势。而计算机通信交流技术则是网络协同办公的技术的核心。本文介绍了计算机通信交流技术在协同办公中的作用,进而对其最基础与重要的的即时通讯技术进行概述,介绍了局域网即时通讯技术的主流技术,并给出了架构实例。     

Constraining peripheral perception in instant messaging during software development by continuous work context extraction

Colocated software development teams benefit from natural work context building, which occurs mainly thanks to the team members, virtually, being forced to listen to what others are talking about. They absorb the information not by directing their attention to the communication, but by being exposed to it and perceiving it peripherally. The same effect of peripheral perception can be enforced with instant messaging, which is a predominant way of communication in distributed teams. However, forcing team members to observe too many and mostly unrelated message notifications can be distracting and causing unnecessary work interruption. This paper presents an approach and tool that ensure peripheral perception in instant messaging constrained by a continuously extracted work context. This is achieved by maintaining a personal work context from developer activities and using this context to filter instant messages to be displayed. A four-week experiment carried out with one of the teams of seven members in the Team Project course at our university indicates that message filtering based on continuous work context extraction performs better over common channel based filtering (as available in Slack). More precisely, message filtering based on continuous work context extraction decreases work interruption and distraction.

     

微机网中的电子信件邮递系统

电子信件邮递系统(EMS)是工作在计算机网络上的信息发送、接收和管理系统,是办公室 自动化系统中的先进通讯手段. 本文简要描述了运行在东北工学院微机网络上的EMS,该系统可以从某一工作站发送一 封信件或转发收到的信件到另一个站,也可发送一封广播信件到网络上的所有站,并提供了 两站之间通过键盘和屏幕直接对话的功能. 文中论述了该系统的结构、邮递服务协议、邮递方式、信箱的管理及信件的保密和存取控 制手段等问题.     

MQTT协议在Android平台上的研究与应用

MQTT是一种基于发布/订阅的轻量级消息传输协议,它的出现为Android平台上实现消息推送提供了新的途径. 针对Android平台消息推送协议的需求,研究了MQTT协议的结构及消息格式,对比分析了Android平台上其他消息推送方案,设计并实现了一款基于MQTT协议的即时通信应用,完成了登录/注册、即时通信、好友管理等功能. 测试结果表明此应用能够满足即时通信应用的基本功能及需求.     

A scalable framework for mobile real-time group communication services

A scalable framework for mobile real-time group communication services is developed in this paper. Examples for possible applications of this framework are mobile social networks, mobile conference calls, mobile instant messaging services, and mobile multi-player on-line games. A key requirement for enabling a real-time group communication service is the tight constraint imposed on the call delivery delay. Since establishing such communication service for a group of independent mobile users under a tight delay constraint is NP-hard, a two-tier architecture is proposed, that can meet the delay constraint imposed by the real-time service requirement for many independent mobile clients in a scalable manner. This goal is achieved by two dimensional partition of the space, first by organization and then geographically. Both the time and memory complexity associated with the location management of N mobile users are O(N) for the location management provided by the proposed framework, while a distributed scheme requires O(N²) for both time and memory complexity.     

A Three-Layer Secure Architecture for IP Multimedia Subsystem-Based Instant Messaging

ABSTRACT

A packet-based network to provide telecommunication services independent from the underlying access and transport technologies is known as a next generation network. An IP multimedia subsystem (IMS) provides an architectural framework for the next generation networks and includes variety of services such as presence, instant messaging, push-to-talk over cellular, multiparty conference, and so forth. IMS-based instant messaging is available in two flavors (immediate messaging and session-based messaging). Both flavors are subject to different types of security threats. An attacker can generate an immediate messaging flood by sending enormous number of messages to deny the services to a group of users or to an individual. Session-based messaging is facing threats such as invite flooding attack, session modification attack, and session teardown attack. In this paper, we developed a security mechanism, consisting of three layers, to secure the messaging service from flooding attacks and session-based attacks and the like. The simulation results show a good improvement in the existing security mechanism of the IMS-based instant messaging service.     

Push-to-Talk Social Talk

This paper presents an exploratory study of college-age students using two-way, push-to-talk cellular radios. We describe the observed and reported use of cellular radio by the participants. We discuss how the half-duplex, lightweight cellular radio communication was associated with reduced interactional commitment, which meant the cellular radios could be used for a wide range of conversation styles. One such style, intermittent conversation, is characterized by response delays. Intermittent conversation is surprising in an audio medium, since it is typically associated with textual media such as instant messaging. We present design implications of our findings.     

Evaluation of Methods for the Determination of Factors Inducing Fatigue in Man at Work

The aim of the study was to determine the influence of textual feedback on the content and outcome of spoken interaction with a natural language dialogue system. More specifically, the assumption that textual feedback could disrupt spoken interaction was tested in a human–computer dialogue situation. In total, 48 adult participants, familiar with the system, had to find restaurants based on simple or difficult scenarios using a real natural language service system in a speech-only (phone), speech plus textual dialogue history (multimodal) or text-only (web) modality. The linguistic contents of the dialogues differed as a function of modality, but were similar whether the textual feedback was included in the spoken condition or not. These results add to burgeoning research efforts on multimodal feedback, in suggesting that textual feedback may have little or no detrimental effect on information searching with a real system.

Statement of Relevance: The results suggest that adding textual feedback to interfaces for human–computer dialogue could enhance spoken interaction rather than create interference. The literature currently suggests that adding textual feedback to tasks that depend on the visual sense benefits human–computer interaction. The addition of textual output when the spoken modality is heavily taxed by the task was investigated.     

基于点对点即时信息交换安全通信协议模型研究

基于点对点即时信息交换在互联网中的应用十分普及,在给人们提供快捷方便的通信服务的同时,也带来了许多安全威胁,针对点对点即时信息交换的攻击越来越频繁。文章基于信息加密理论和点对点即时通信技术的特点,提出了点对点即时信息交换安全通信协议模型,并对该模型所面临的主要安全性进行了分析。     

即时消息系统的好友关系网络拓扑建模与分析

即时消息系统目前已成为人们交友和沟通的主要工具,建模和理解其中的好友关系网络的建立和演化规律对于设计更加友好的即时消息系统很有益处.针对世界最大的即时消息系统之一的QQ,分析了好友关系网络的特点,统计了QQ用户的交友取向特征,考虑了实际的QQ联系人作为节点的出度和入度情况.不同于传统的基于节点度的优先附着规则,提出了即...