Secure instant messaging in enterprise-like networks

Instant messaging (IM) has been one of most frequently used malware attack vectors due to its popularity. However, previous solutions are ineffective to defend against IM malware in an enterprise-like network environment, mainly because of high false positive rate and the requirement of the IM server being inside the protected network. In this paper, we propose a novel IM malware detection and suppression mechanism, HoneyIM, which guarantees almost zero false positive on detecting and blocking IM malware in an enterprise-like network. The detection of HoneyIM is based on the concept of honeypot. HoneyIM uses decoy accounts to trap IM malware by leveraging malware spreading characteristics. Fed with accurate detection results, the suppression of HoneyIM can conduct a network-wide blocking. In addition, HoneyIM delivers attack information to network administrators in real-time so that system quarantine and recovery can be quickly performed. The core design of HoneyIM is generic, and can be applied to the scenarios that either enterprise IM services or public IM services are used in the protected network. Based on open-source IM client Pidgin and client honeypot Capture, we build a prototype of HoneyIM and validate its efficacy through both simulations and real experiments. Our results show that HoneyIM provides effective protection against IM malware in enterprise-like networks.     

OKCM: improving parallel task scheduling in high-performance computing systems using online learning

The Journal of Supercomputing - Task scheduling is becoming increasingly important in large-scale high-performance computing real-time systems as the parallel scale, number and types of task...     

Application of TPB to punctuation usage in instant messaging

Instant messaging (IM) is being widely used in the workplace and personal life at an accelerated rate. In this paper, we empirically investigate an extension of TPB (Theory of Planned Behaviour) model to explain why individuals use punctuation in IM. Conceptually, we examine attitude and behavioural belief and their impacts on punctuation usage. Our research model was tested in an empirical study, which confirmed all of our hypotheses. This paper also explains why people prefer to use punctuation in IM and how the usage is moderated by the communication context.     

Privacy in instant messaging: an impression management model

Instant messaging (IM) has evolved into an important tool for collaborative work. It supports informal near-synchronous communication and fosters awareness of the online presence of one's communication partners. Like all awareness systems, IM runs into concerns regarding privacy. Drawing upon prior literature and exploratory interviews, we postulate a model that posits impression management as an underlying cause for privacy desires of IM users. We verify our hypotheses using linear structural modelling on data from a large online survey of IM users across the US. The model establishes that the desire for privacy in IM arises due to the desire for impression management (both directly, as well as indirectly through the desire for visibility of one's impression to oneself). Based on this model, we suggest that IM systems could support privacy needs of users better by providing them with more knowledge and control over aspects that affect their IM-conveyed impression on others (i.e. by making impression management functionality available). Specifically, to help convey and sustain appropriate impressions on IM contacts, IM systems should allow for increased visibility of one's actions to oneself, facilitate easy comparison of one's practices with those of others, and allow one to view oneself from the perspective of others and to make finer-grained adjustments to IM settings than is possible today.     

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.

     

基于XMPP的即时通信网关应用研究

XMPP最终要实现不同即时通信系统间的互通。主要介绍对XMPP与其他IM互连互通的网关原理及其应用进行的研究讨论,并以jabber系统与MSN Messenger进行互发信息作为实例进行详细阐述。     

Facilitating the legislation process using a shared conceptual model

The Power (Program for an Ontology-based Working Environment for Rules and regulations) research program combines a knowledge-capitalization/knowledge-codification approach with an organization-dynamics approach. Initial results indicate that this method will help to improve the quality of law enforcement and decrease the time needed for implementing legislation and regulation changes.     

Optimal design of truss structures using parallel computing

Parallel design optimization of large structural systems calls for a multilevel approach to the optimization problem. The general optimization problem is decomposed into a number of non-interacting suboptimization problems on the first level. They are controlled from the second level through coordination variables. Thus, the solutions of the independent first-level subsystems are directed towards the overall system optimum. In the present paper, optimal design of truss structures using parallel computing technique is described. In this method, optimization of a large truss structure has been carried out by decomposing the structure into sub-domains and suboptimization tasks. Each sub-domain has independent design variables and a small number of behaviour constraints. The two-level sub-domain optimum design approach is summarized by several numerical examples with speedups and efficiencies of algorithms on message passing systems. It has been noticed that the efficiency of the algorithm for design optimization increases with the size of the structure.     

Text-making practices beyond the classroom context: Private instant messaging in Hong Kong

This article explores the ways in which instant messaging (IM) texts are produced by a group of university students in Hong Kong. Even though there exists a body of research on linguistic issues of computer-mediated communication (CMC) in non-Western contexts, much emphasis has been placed on the features of CMC English used by ESL learners. Instead of focusing on one particular language, this article reports on a number of language-related issues that are specific to the Hong Kong CMC context such as the use of Chinese and English, invented Cantonese spellings, and code-mixing. Drawing upon qualitative data such as observational notes and interviews, my study analyzes the text-making practices associated with the use of IM (ICQ and MSN Messenger) within the New Literacy Studies (NLS) framework [Gee, James Paul. (1996). Social linguistics and literacies. London: Routledge; Barton, David, Hamilton, Mary, & Ivani?, Roz (Eds.). (2000). Situated literacies, London: Routledge; Street, Brian V. (1998). New literacies in theory and practice: What are the implications for language in education? Linguistics and Education, 10(1), 1-24], which is a social practice approach to the study of reading and writing in real-life contexts. This article concludes by arguing that learning to produce texts in IM involves an entirely different process from that of formal language learning in the classroom. In a multilingual society like Hong Kong, teachers and educators need to be aware of such differences so as to bridge the gap between actual uses of language in students’ private lives and the form of language used in the formal classroom context.     

Facilitating student-driven constructing of learning environments using Web 2.0 personal learning environments

Web 2.0 Personal Learning Environments (PLEs) are becoming a promising area of development in e-Learning. While enhancing students' control over the entire learning process including constructing learning environment appears to be an essential objective of introducing Web 2.0 PLEs to education, there is little consensus on how to attain this objective. In this paper a theory-informed model to facilitate students' engagement in constructing their learning environment using Web 2.0 PLEs is proposed and evaluated. The model consists of four components: student's control dimensions, student-centric instructional approaches, the learning potential of Web 2.0 tools and services, and technology enhanced learning activities. This model is used to conduct a design-based research in the context of a first grade class in a secondary school in the Netherlands consisting of 29 students (18 girls and 11 boys, aged 11–13 year). The results suggest that the model can facilitate students' engagement in constructing their learning environment through influencing communication between teacher and students, involving students in adding tools, resources, and people into their learning environment, and enhancing their feeling of ownership over their learning environment.     

面向机器学习的分布式并行计算关键技术及应用

当前机器学习等算法的计算、迭代过程日趋复杂, 充足的算力是保障人工智能应用落地效果的关键。本文首先提出一种适应倾斜数据的分布式异构环境下的任务时空调度算法,有效提升机器学习模型训练等任务的平均效率;其次,提出分布式异构环境下高效的资源管理系统与节能调度算法,实现分布式异构环境下基于动态预测的跨域计算资源迁移及电压/频率的动态调节,节省了系统的整体能耗;然后构建了适应于机器学习/深度学习算法迭代的分布式异构优化环境,提出了面向机器学习/图迭代算法的分布式并行优化基本方法。最后,本文研发了面向领域应用的智能分析系统,并在制造、交通、教育、医疗等领域推广应用,解决了在高效数据采集、存储、清洗、融合与智能分析等过程中普遍存在的性能瓶颈问题。     

IM中一种新的群拓扑结构——三层K叉树

目前一些主流即时通信软件已经嵌入了聊天群，但都过分地依赖中心服务器，使得聊天群的应用受到限制。给出了聊天群的一种新的拓扑结构——三层K叉树，将中心服务器的负载分担到一些选定的即时通信客户端，以减轻中心服务器的负载，增强聊天群的扩展性。分析和仿真结果表明三层K叉树在不降低聊天群性能的情况下确能达到以上目的。     

用LDL~T并行分解优化大规模SVM的训练效率

支持向量机在大规模训练集上学习时,存在学习时间长、泛化能力下降的问题。研究使用路径跟踪内点法构建面向大规模训练集的SVM学习算法,找到影响算法学习效率的关键是求解大型线性修正方程,首先使用降维法降低修正方程的维数,再使用矩阵LDLT并行分解高效地求解子修正方程,达到优化大规模SVM学习效率的目的,实验结果说明SVM训练效率提升的同时不影响SVM模型的泛化能力。     

The role of big data and cognitive computing in the learning process

In this paper, we investigate how the raise of big data and cognitive computing systems is going to redesign the labor market, also impacting on the learning processes. In this respect, we make reference to higher education and we depict a model of a smart university, which relies on the concepts that are at the basis of the novel smart-cities’ development trends. Thus, we regard education as a process so that we can find specific issues to solve to overcome existing criticisms, and provide some suggestions on how to enhance universities’ performances. We highlight inputs, outputs, and dependencies in a block diagram, and we propose a solution built on a new paradigm called smarter-university, in which knowledge grows rapidly, is easy to share, and is regarded as a common heritage of both teachers and students. Among the others, a paramount consequence is that there is a growing demand for competences and skills that recall the so called T-shape model and we observe that this is pushing the education system to include a blend of disciplines in the curriculums of their courses. In this overview, among the wide variety of recent innovations, we focus our attention on cognitive computing systems and on the exploitation of big data, that we expect to further accelerate the refurbishment process of the key components of the knowledge society and universities as well.     

Implementing collaborative learning activities in the classroom supported by one-to-one mobile computing: A design-based process

Mobile devices such as PDAs, smartphones and tablet computers are becoming increasingly popular, setting out opportunities for new ways of communicating and collaborating. Research initiatives have ascertained the potential of mobile devices in education, and particularly, the benefits of incorporating them in the classroom for eliciting collaborative learning and active student participation. However, the development of technology-supported learning environments poses challenges to education researchers, practitioners, and software technologists in creating educational tools that respond to real needs of instructors and learners, meet clearly defined didactic purposes, and are practical for the intended audience. This article reports on a technology for facilitating the implementation of collaborative learning environments in the classroom supported by one-to-one mobile computing. The approach encompasses a framework supporting the design and implementation of the mobile software, and a design-based process that guides interdisciplinary efforts utilizing the framework, towards creating effective pedagogical models based on collaborative learning. The proposed design-based process allowed us to develop pedagogical models that respond to real needs of learners and instructors, where development is grounded on rigorous scientific research, allowing to reuse both knowledge and software, and showing an improvement of the mobile software built based on continuous experimentation and evaluation. A case study illustrating the application of the technology is presented and plans for future research are discussed.     

Exploring the impact of instant messaging on subjective task complexity and user satisfaction

Instant messaging (IM) technologies are being rapidly deployed in the workplace. Current studies largely focus on the adoption of IM and how IM is used. Little research has been conducted to understand the potential impact of using IM in the workplace. This paper theorizes and empirically tests how the frequency of IM interruptions and the position power of message sender could interact with an individual’s polychronic orientation, that is, multitasking preference, and jointly influence employee satisfaction and subjective task complexity. The present study illustrates that polychronic knowledge workers are more satisfied with the multitasking work process deploying IM technology than monochronic ones. In addition, the effect of interruptions is dependent upon an individual’s polychronic orientation. The increase in interruption frequency only reduces the process satisfaction of monochronic individuals but not polychronic individuals. Further, the polychronic orientation of message receivers also influences how they process information. When IM messages are sent from their supervisors, monochronic individuals tend to prioritize tasks and perceive a lower level of overall task complexity. The information processing of polychronic individuals seem to be less influenced by the position power of message sender.     

A simulated annealing algorithm for zoning in planning using parallel computing

There is an increasing demand for tools that support land use planning processes, particularly the design of zoning maps, which is one of the most complex tasks in the field. In this task, different land use categories need to be allocated according to multiple criteria. The problem can be formalized in terms of a multiobjective problem. This paper generalizes and complements a previous work on this topic. It presents an algorithm based on a simulated annealing heuristic that optimizes the delimitation of land use categories on a cadastral parcel map according to suitability and compactness criteria. The relative importance of both criteria can be adapted to any particular case. Despite its high computational cost, the use of plot polygons was decided because it is realistic in terms of technical application and land use laws. Due to the computational costs of our proposal, parallel implementations are required, and several approaches for shared memory systems such as multicores are analysed in this paper. Results on a real case study conducted in the Spanish municipality of Guitiriz show that the parallel algorithm based on simulated annealing is a feasible method to design alternative zoning maps. Comparisons with results from experts are reported, and they show a high similarity. Results from our strategy outperform those by experts in terms of suitability and compactness. The parallel version of the code produces good results in terms of speed-up, which is crucial for taking advantage of the architecture of current multicore processors.     

Dynamic broadcasting in parallel computing

We consider the problem where broadcast requests are dynamically generated at random time instants at each node of a multiprocessor network. In particular, in our model packets arrive at each node of a network according to a Poisson process, and each packet has to be broadcast to all the other nodes. We propose an on-line, distributed routing scheme to execute the broadcasts in this dynamic environment. Our scheme consists of repeated execution of a partial multinode broadcast task, which is a static communication task where any M⩽N arbitrary nodes of an N-processor network broadcast a packet to all the other nodes. The dynamic broadcasting scheme that we propose can be used in any topology, regular or not, for which partial multinode broadcast algorithms with certain properties can be found. We derive such an algorithm and we analyze the corresponding dynamic broadcasting scheme for the hypercube network. We show that its stability region tends to the maximum possible as the number of nodes of the hypercube tends to infinity. Furthermore, for any fixed load in the stability region, the average delay is of the order of the diameter of the hypercube. Our analysis does not use any approximating assumptions