Improving the match between callers and receivers: A study on the effect of contextual information on cell phone interruptions

A problem with the location-free nature of cell phones is that callers have difficulty predicting receivers' states, leading to inappropriate calls. One promising solution involves helping callers decide when to interrupt by providing them contextual information about receivers. We tested the effectiveness of different kinds of contextual information by measuring the degree of agreement between receivers' desires and callers' decisions. In a simulation, five groups of participants played the role of ‘Callers’, choosing between making calls or leaving messages, and a sixth group played the role of ‘Receivers’, choosing between receiving calls or receiving messages. Callers were provided different contextual information about Receivers' locations, their cell phones' ringer state, the presence of others, or no information at all. Callers provided with contextual information made significantly more accurate decisions than those without it. Our results suggest that different contextual information generates different kinds of improvements: more appropriate interruptions or better avoidance of inappropriate interruptions. We discuss the results and implications for practice in the light of other important considerations, such as privacy and technological simplicity.     

Knowledge Management in Locating the Patient in an Emergency Medical Service in Italy

This study examines an Emergency Medical Service in order to analyze the composite set of activities and instruments directed at locating the patient. The good management of information about the location of the emergency is highly relevant for a reliable rescue service, but this information depends on knowledge of the territory that is socially distributed between EMS operators and callers. Accordingly, the decision-making process often has to go beyond the emergency service protocols, engaging the operator in undertaking an open negotiation in order to transform the caller’s role from layman to “co-worker”. The patient’s location turns out to be an emerging phenomenon, collaborative work based on knowledge management involving two communities—the callers and the EMS operators—that overlap partially. Drawing examples from emergency calls, the study analyzes the practice of locating a patient as a complex and multi-layered process, highlighting the role played by new and old technologies (the information system and the paper maps) in this activity. We argue that CSCW technologies enable the blended use of different kinds of instruments and support an original interconnection between the professional localization systems and the public’s way of defining a position.     

Formative feedback to transfer self‐regulation of task‐oriented reading strategies

The study includes two experiments to analyse the effects of automatic formative feedback designed to promote the transfer of self‐regulation of strategic decisions in task‐oriented reading (e.g. answering questions from an available text). Secondary‐school students read and answered multiple‐choice comprehension questions from two texts having them available while receiving consistent feedback about their performance and strategic decisions. Then, they read a different text and answered questions also with the text available, but receiving no feedback. In Experiment 1, we tested two feedback procedures that differed in task conditions and the feedback information associated to these conditions. The most effective was a procedure that forced students to select relevant text information to answer each question and provided accurate feedback based on that selection. Experiment 2 was designed to disentangle the role played by the selection task from that played by the feedback provided. We found that the two components contribute to transfer the self‐regulation strategies, although each one has a specific role for different strategies. Theoretical and practical implications of the studies are discussed.     

Contextual web searches in Facebook using learning materials and discussion messages

The web is nowadays one of the main information sources, and information search is an important area in which many advances have been registered. One approach to improve web search results is to consider contextual information. Usually, information about context has been provided through user logs on previous searches or the monitoring of clicks on first results, but different approaches can be used in specific environments. In a web based learning environment, existing documents and exchanged messages could provide contextual information. So, the main goal of this work is to provide a contextual web search engine based on shared documents and messages posted in a social network used for collaborative learning. Contextual search is provided through query expansion using learning documents (material provided by the teacher) and discussion messages (posts, links and comments that result from the participants’ interactions). A prototype was implemented and used in a learning scenario to acquire the context in a learning community. The proposed approach makes the context acquisition faster and more dynamic as it considers an automatic approach over text processing of documents and discussions. In addition, the results of the query engine with and without the contextual information were compared and the proposed approach using contextual information showed improvements in the precision of the results.     

An analysis of students’ spontaneous computer-mediated help seeking: A step toward the design of ecologically valid supporting tools

This study analyzes middle school students’ spontaneous mathematics-related help-seeking behavior, in view of making ecologically valid recommendations for the design of supporting tools or “help systems”. Our aim was to investigate the content of students’ help-seeking messages – Are there different forms of help-seeking messages and do they evolve with age? We used the archives of a French forum that provides students with free individualized help in mathematics. The data consisted of 206 messages sent by French middle school students over a period of 42 months. The constituent categories of the messages were identified. The results showed that not all middle school students use the same help-seeking “format”. Compared to sixth graders, ninth graders wrote messages containing more constituent categories, i.e., they provided the online expert with more kinds of information. A detailed analysis of the categories further showed that older students’ messages more often contained explicit help requests and contextual information than did younger students’ messages. Thus, the messages of the oldest students (age 15) were both cognitively more understandable and socially more acceptable than those of the youngest students (age 11). The interpretation of these findings and their implications for designing help systems are discussed.     

基于HLA的潜艇作战仿真系统时间管理研究

时间管理服务是运行支撑系统(run-time infrastructure,RTI)提供的6类服务之一,它按照高层体系结构接口规范来管理各类消息的发送和接收,并协调不同的时间推进机制,以保证分布式仿真的逻辑正确性.针对仿真驱动的潜艇实装作战仿真训练系统,结合HLA时间管理常见问题,从开发基于HLA仿真应用的角度分析了时间管理机制,重点研究了潜艇作战仿真训练系统中的推演时间管理方法.     

The effect of management structure on the performance of interconnected packet-switched networks

A multi-layer model is used to study the effect of management structure on the performance of connection-oriented packet-switched networks managed via fixed threshold call admission policies. Call admission decisions are based on estimates of the number and characteristics of currently held calls, which may be inaccurate due to uncertainties in the measurement process or to the use of untimely information. Let the state estimate be represented as the true state value offset by a noise factor. The standard deviation of the estimation error serves as a key parameter in representing the complexity, coverage, extensiveness, and cost of the implemented network management and information collection procedure. For a single-domain network the effects of Gaussian noise on blocking, throughput, and the probability of excess calls are examined and used to define a measure of performance, the throughput capacity trajectory, which gives maximum throughput levels for fixed packet blocking, packet delay, and probability of excess call constraints. In a multi-domain network a particular network manager/controller may have complete information about its own domain, but limited, aggregated, or untimely information about other domains. Tradeoffs between centralized and distributed decision-making are discussed and a mechanism is provided for comparing various management structures as well as determining good values for admission control thresholds.     

A Comparison of Dialog Strategies for Call Routing

Advances in commercially-available ASR technology have enabled the deployment of “How-may-I-help-you?” interactions to automate call routing. While often preferred to menu-based or directed dialog strategies, there is little quantitative research into the relationships among prompt style, task completion, user preference/satisfaction, and domain. This work applies several dialog strategies to two domains, drawing on both real callers and usability subjects. We find that longer greetings produce higher levels of first-utterance routability. Further, we show that a menu-based dialog strategy produces a uniformly high level of routability at the first utterance in two domains, whereas an open-dialog approach varies significantly with domain. In a domain where users lack an expectation of task structure, users are most successful with a directed strategy, for which preference scores are highest, even though it does not result in the shortest dialogs. Callers rarely provide more than one piece of information in their responses to all types of dialog strategies. Finally, a structured dialog repair prompt is most helpful to callers who were greeted with an open prompt, and least helpful to callers who were greeted with a structured prompt.     

Journey decision making: the influence on drivers of dynamic information presented on variable message signs

In many highways environments electronic media such as variable message signs are increasingly being used to provide drivers with up-to-date dynamic information in order to influence driving decision making during journeys. These decisions may be associated with strategic choices, such as route selection, or tactical decisions, such as driving at a certain speed, or altering driving style. This paper presents a study that used two methods—a scenario approach and a medium-fidelity driving simulator. Data from both methods are presented here and include decision making and driving performance data. These data provide an insight into the role of information and other contextual influences in decision making in the driving context specifically, but also has useful implications for the way in which information should be designed in other decision making contexts, such as travel using public transport, or supporting real-time complex control operations. The use of multiple data collection approaches also enabled data comparisons to be made, thus improving overall confidence in conclusions. The paper highlights the role of familiarity with information wording and context, level of detail, interpreted meaning, previous experience and contextual cues on trust in information and consequently behaviour in response to the information presented.     

Let's Have a Conversation

Communicating inside a single program is trivial: one method calls another, the result comes back, and the calling method continues. If anything goes wrong, an exception is thrown. If the program aborts altogether, both caller and callee share the same fate, making the interaction an all-or-nothing affair. This kind of binary outcome is a welcome behavior in the predictive world of computer software, especially one that's based on 1s and 0s. In the land of loosely coupled distributed systems, things are a little more complicated. Using procedure call semantics for distributed systems is generally considered a bad idea, so systems should communicate in a more loosely coupled way - preferably by exchanging messages. Message-based communication results in a simple interaction model and, if used with message queues, temporal decoupling between sender and receiver: splitting the request-response interaction into two separate messages means that callers don't have to sit around waiting for response messages     

ConChat: a context-aware chat program

ConChat is a context-aware chat program that enriches electronic communication by providing contextual information and resolving potential semantic conflicts between users.ConChat uses contextual information to improve electronic communication. Using contextual cues, users can infer during a conversation what the other person is doing and what is happening in his or her immediate surroundings. For example, if a user learns that the other person is talking with somebody else or is involved in some urgent activity, he or she knows to expect a slower response. Conversely, if the user learns that the other person is sitting in a meeting directly related to the conversation, he or she then knows to respond more quickly. Also, by informing users about the other person's context and tagging potentially ambiguous chat messages, ConChat explores how context can improve electronic communication by reducing semantic conflicts.     

Tactful calling: investigating asymmetric social dilemmas in mobile communications

Recipients of phone calls face a constant dilemma between ignoring calls at the possible expense of offending the caller, missing business opportunities or neglecting family members on one hand; and answering them at the expense of interrupting their train of thought or appearing rude and impolite towards others with whom they share a social activity on the other hand. We studied people's attitudes regarding these dilemmas, with emphasis on their social aspects. In a cross-cultural study, conducted in Israel and in Germany, we surveyed both caller and recipient attitudes towards answering mobile phone calls in various circumstances. The study also assessed the aspects of providing contextual information about a call prior to it being answered, including types of information deemed most valuable. The results emphasise the importance of social norms in affecting respondents’ attitudes towards making or accepting phone calls regardless of role (caller or recipient), gender or culture. We also found that the norms in the physical context (e.g. being in a meeting) prevailed over norms in the virtual context (e.g. the phone call). Cultural and gender differences did not affect the degree to which people were frustrated by insufficient information regarding the other party's context. However, these factors did affect the suggested design solutions to this problem. The research provides insight into the social aspects of the problem of interruptive mobile phone calls and towards designing applications that help users maintain politeness while handling the caller–recipient dilemma.     

Markov chain models of a telephone call center with call blending

Motivated by a Bell Canada call center operating in blend mode, we consider a system with two types of traffic and two types of agents. Outbound calls are served only by blend agents, whereas inbound calls can be served by either inbound-only or blend agents. Inbound callers may balk or abandon. There are several performance measures of interest, including the rate of outbound calls and the proportion of inbound calls waiting more than some fixed number of seconds. We present a collection of continuous-time Markov chain (CTMC) models which capture many real-world characteristics while maintaining parsimony that results in fast computation. We discuss and explore the tradeoffs between model fidelity and efficacy and compare our different CTMC models with a realistic simulation model of a Bell Canada call center, used as a benchmark.     

Distinguishing re-sharing behaviors from re-creating behaviors in information diffusion

Social media plays a fundamental role in the diffusion of information. There are two different ways of information diffusion in social media platforms such as Twitter and Weibo. Users can either re-share messages posted by their friends or re-create messages based on the information acquired from other non-local information sources such as the mass media. By analyzing around 60 million messages from a large micro-blog site, we find that about 69 % of the diffusion volume can be attributed to users’ re-sharing behaviors, and the remaining 31 % are caused by user re-creating behaviors. The information diffusions caused by the two kinds of behaviors have different characteristics and variation trends, but most existing models of information diffusion do not distinguish them. The recent availability of massive online social streams allows us to study the process of information diffusion in much finer detail. In this paper, we introduce a novel model to capture and simulate the process of information diffusion in the micro-blog platforms, which distinguishes users’ re-sharing behaviors from re-creating behaviors by introducing two different components. Thus, our model not only considers the effect of the underlying network structure, but also the influence of other non-local information sources. The empirical results show the superiority of our proposed model in the fitting and prediction tasks of information diffusion.     

Formal analysis for robust anti-SPIT protection using model checking

Anti-SPIT policies counter the SPam over Internet Telephony (SPIT) by distinguishing bots launching unsolicited bulks of VoIP calls from human beings. We propose an Anti-SPIT Policy Management mechanism (aSPM) that detects spam calls and prevents VoIP session establishment by the Session Initiation Protocol (SIP). The SPIN model checker is used to formally model and analyze the robustness of the aSPM mechanism in execution scenarios with parallel SIP sessions. In case of a possible design flaw, the model checker provides a trace of the caught unexpected behavior (counterexample), that can be used for the revision of the mechanism’s design. Our SPIN model is parameterized, based on measurements from experiments with VoIP users. Non-determinism plays a key role in representing all possible anti-SPIT policy decisions, in terms of the SIP messages that may be exchanged. The model checking results provide evidence for the timeliness of the parallel SIP sessions, the absence of deadlocks or livelocks, and the fairness for the VoIP service users. These findings ensure robust anti-SPIT protection, meaning that the aSPM mechanism operates as expected, despite the occurrence of random SPIT calls and communication error messages. To the best of our knowledge, this is the first analysis for exhaustively searching security policy flaws, due to complex interactions between anti-SPIT measures and the SIP protocol services.     

基于Android平台的盲人手机系统设计与开发

人们生活中的绝大部分信息都是通过视觉获得的,所以盲人能够从外界获取的信息量很少,但这并不能阻止他们努力提高生活质量的渴望。智能手机的快速发展给盲人提供了前所未有的机遇。开发盲人手机具有极大的应用价值。该文主要介绍了在Android平台上设计和实现的一款盲人手机系统,该系统使用了语音识别、语音合成及Web Service等相关技术,实现了语音拨打电话、语音接听电话、语音发送短信、语音播报来电短信、语音报时、语音播报日期和语音播报天气等功能,并能在Android手机中稳定运行,方便盲人使用手机,具有较高的实用价值。     

An analysis of students’ spontaneous computer-mediated help seeking: A step toward the design of ecologically valid supporting tools

This study analyzes middle school students’ spontaneous mathematics-related help-seeking behavior, in view of making ecologically valid recommendations for the design of supporting tools or “help systems”. Our aim was to investigate the content of students’ help-seeking messages – Are there different forms of help-seeking messages and do they evolve with age? We used the archives of a French forum that provides students with free individualized help in mathematics. The data consisted of 206 messages sent by French middle school students over a period of 42 months. The constituent categories of the messages were identified. The results showed that not all middle school students use the same help-seeking “format”. Compared to sixth graders, ninth graders wrote messages containing more constituent categories, i.e., they provided the online expert with more kinds of information. A detailed analysis of the categories further showed that older students’ messages more often contained explicit help requests and contextual information than did younger students’ messages. Thus, the messages of the oldest students (age 15) were both cognitively more understandable and socially more acceptable than those of the youngest students (age 11). The interpretation of these findings and their implications for designing help systems are discussed.     

GSM短信模块开发及其应用

为了扩展监控系统报警方式，对基于GSM短信进行通信的技术进行了研究。基于SIEMENSTC35I核心模块，研制了一种GSM办公终端硬件，可通过电脑控制设备完成普通短信收发。对办公终端的控制方法进行封装，提供了动态链接库和数据库中间件两种二次开发接口。压力测试和实际应用表明，该GSM模块达到400-600条短信／小时的吞吐能力，具有一定的实际使用价值。     

Network Selection Decisions for Multiple Calls Based on Consensus Level

Next generation multimode terminals have the capability to support different classes of calls simultaneously as well as the ability to connect to two or more radio access technologies (RATs), at the same time, in a heterogeneous wireless network. For a mobile terminal having multiple classes of simultaneous handoff calls (such as file download and video sessions), RAT selection decisions can be made independently for individual calls in the group or jointly for the entire group of calls. Both independent and group RAT selection decisions for multiple calls have advantages and disadvantages. Existing RAT selection algorithms have focused on RAT selection decisions for single calls. Therefore, this paper investigates independent call and group call RAT selection decisions for multiple calls in heterogeneous wireless networks, and proposes a scheme that makes RAT selection decisions for multiple calls based on a consensus level among the multiple calls to be admitted. When this consensus level is among multiple calls to be admitted into a particular RAT and is equal to or above a certain threshold value, a group decision is used. Otherwise, independent decisions are made. The performance of the proposed RAT selection scheme is evaluated in a three service three RAT heterogeneous network, supporting multihomed terminals. Simulation results are given to show the effectiveness of the proposed scheme.