Additional Communication Channel Research Articles

A Binary Communication Channel With Memory Based on a Finite Queue

A model for a binary additive noise communication channel with memory is introduced. The channel noise process, which is generated according to a ball sampling mechanism involving a queue of finite length M, is a stationary ergodic Mth-order Markov source. The channel properties are analyzed and several of its statistical and information-theoretical quantities (e.g., block transition distribution, autocorrelation function (ACF), capacity, and error exponent) are derived in either closed or easily computable form in terms of its four parameters. The capacity of the queue-based channel (QBC) is also analytically and numerically compared for a variety of channel conditions with the capacity of other binary models, such as the well-known Gilbert-Elliott channel (GEC), the Fritchman channel, and the finite-memory contagion channel. We also investigate the modeling of the traditional GEC using this QBC model. The QBC parameters are estimated by minimizing the Kullback-Leibler divergence rate between the probability of noise sequences generated by the GEC and the QBC, while maintaining identical bit-error rates (BER) and correlation coefficients. The accuracy of fitting the GEC via the QBC is evaluated in terms of ACF, channel capacity, and error exponent. Numerical results indicate that the QBC provides a good approximation of the GEC for various channel conditions; it thus offers an interesting alternative to the GEC while remaining mathematically tractable.

Berlin Brain–Computer Interface—The HCI communication channel for discovery

The investigation of innovative Human–Computer Interfaces (HCI) provides a challenge for future interaction research and development. Brain–Computer Interfaces (BCIs) exploit the ability of human communication and control bypassing the classical neuromuscular communication channels. In general, BCIs offer a possibility of communication for people with severe neuromuscular disorders, such as amyotrophic lateral sclerosis (ALS) or complete paralysis of all extremities due to high spinal cord injury. Beyond medical applications, a BCI conjunction with exciting multimedia applications, e.g., a dexterity discovery, could define a new level of control possibilities also for healthy customers decoding information directly from the user's brain, as reflected in EEG signals which are recorded non-invasively from the scalp. This contribution introduces the Berlin Brain–Computer Interface (BBCI) and presents set-ups where the user is provided with intuitive control strategies in plausible interactive bio-feedback applications. Yet at its beginning, BBCI thus adds a new dimension in HCI research by offering the user an additional and independent communication channel based on brain activity only. Successful experiments already yielded inspiring proofs-of-concept. A diversity of interactive application models, say computer games, and their specific intuitive control strategies are now open for BCI research aiming at a further speed up of user adaptation and increase of learning success and transfer bit rates. BBCI is a complex distributed software system that can be run on several communicating computers responsible for (i) the signal acquisition, (ii) the data processing and (iii) the feedback application. Developing a BCI system, special attention must be paid to the design of the feedback application that serves as the HCI unit. This should provide the user with the information about her/his brain activity in a way that is intuitively intelligible. Exciting discovery applications qualify perfectly for this role. However, most of these applications incorporate control strategies that are developed especially for the control with haptic devices, e.g., joystick, keyboard or mouse. Therefore, novel control strategies should be developed for this purpose that (i) allow the user to incorporate additional information for the control of animated objects and (ii) do not frustrate the user in the case of a misclassification of the decoded brain signal. BCIs are able to decode different information types from the user's brain activity, such as sensory perception or motor intentions and imaginations, movement preparations, levels of stress, workload or task-related idling. All of these diverse brain signals can be incorporated in an exciting discovery scenario. Modern HCI research and development technologies can provide BCI researchers with the know-how about interactive feedback applications and corresponding control strategies.

NEW TEACHING AND LEARNING TECHNOLOGIES FOR INTERACTIVE LECTURES

Conventional lectures in large classrooms come with fundamental didactic problems due to a lack of interactivity and feedback opportunities. In an interactive lecture each student is equipped with a light-weight, mobile device that can be used to interact with the lecturer during the lesson, thus creating an additional channel of communication. These devices support new teaching and learning paradigms such as participatory simulations. We present our experiences with the usage of mobile devices in lectures. After discussing the didactic benefits of interactive lectures, we introduce the software toolkits used in our scenarios, we highlight selected tools such as a quiz tool or a support tool for participatory simulation, and present major results from six pedagogical studies we have conducted.

Evaluation of Spoken Dialogue Technology for Real-Time Health Data Collection

Background A real-time assessment of patients’ experiences is an important methodology for studies in health care, quality of life, behavioral sciences, and new drug and treatment development. Ecological momentary assessment is a methodology that allows for real-time assessment of experience and behavior in a subject’s natural environment. Recently, electronic data collection techniques have been introduced, including systems utilizing interactive voice response.Objective The objective of this project was evaluation of spoken dialogue methodology for real-time data collection of information from patients for health, behavioral, and lifestyle studies and monitoring. While the management of the data collection process was Internet-based, this additional eHealth communication channel was based on over-the-phone natural language conversation with a dialogue system utilizing automated speech recognition technology. For this study we implemented a dialogue system for patients’ assessment and monitoring of chronic pain.Methods Experimental evaluation of usability of the Pain Monitoring Voice Diary was performed with 24 volunteers. The volunteers were asked to contribute 10 sessions with the system over a period of 2 weeks; in practice, the number of sessions per subject ranged from 1 to 20. The subjects were asked to either relate to pain episodes in their past while answering the system’s questions, or use as a guidance one of nine provided medical scenarios compiled by a pain specialist, ranging from migraines and back pain to post-surgical pain (knee injury) and cancer- and chemotherapy-related afflictions.Results From 24 volunteers, we collected a total of 177 dialogue sessions: 171 sessions were completed, while the caller hung up in the other 6 sessions. There were a total of 2437 dialogue turns, where a dialogue turn corresponds to one system prompt and one user utterance. The data capture rate, measuring the percentage of slots filled automatically, was 98%, while the other 2% were flagged for transcription. Among the utterances sent to transcription, where the user had opted for the “none of those” option, 70% corresponded to the “type of pain” slot, 20% to the “symptoms” slot, and 10% to the “body part” slot, indicating that those are the grammars with the highest out-of-vocabulary rate.Conclusions The results of this feasibility study indicated that desired accuracy of data can be achieved with a high degree of automation (98% in the study) and that the users were indeed capable of utilizing the flexible interface, the sessions becoming more and more efficient as users’ experience increased, both in terms of session duration and avoidance of troublesome dialogue situations.

Relationship marketing and brand involvement of professionals through web-enhanced brand communities: the case of Coloplast

More and more firms are recognizing the advantages of web-enhanced brand communities as a lever for relationship-marketing communication. Brand communities, not only provide companies with an additional communication channel, but also allow the possibility of establishing linkages to devoted users. So far, brand community has only been discussed in relation to B2C marketing. However, the effect of using web-enhanced brand communities in a B2B context may be even greater inasmuch as professional users have a strong and long-standing interest in exchanging product-related information. Based on the Coloplast case study, this contribution outlines a conceptual model for linking web-enhanced brand community activities and relationship building in B2B markets.

Relationship marketing and brand involvement of professionals through web-enhanced brand communities: The case of Coloplast

More and more firms are recognizing the advantages of web-enhanced brand communities as a lever for relationship-marketing communication. Brand communities not only provide companies with an additional communication channel, but also allow the possibility of establishing linkages to devoted users. So far, brand community has only been discussed in relation to B2C marketing. However, the effect of using web-enhanced brand communities in a business-to-business (B2B) context may be even greater, inasmuch as professional users have a strong and long-standing interest in exchanging product-related information. Based on the Coloplast case study, this contribution outlines a conceptual model for linking web-enhanced brand community activities and relationship building in B2B markets.

The Continued Relevance of Local Parties in Representative Democracies

This article assesses the value of local parties. It asks why political parties value their local sections. It also considers the ways in which local parties can benefit society. Local parties act as a democratic training ground for party members, are a conduit for political communication and provide parties with a range of resources. They also act as problem solving agencies; they ensure that policy is responsive to local needs; they provide an additional channel of communication and accountability; and they link citizens with the state. The article ends with an appeal to party scholars to refocus their attention towards local parties.

Estimating the mutual information of an EEG-based Brain-Computer Interface.

An EEG-based Brain-Computer Interface (BCI) could be used as an additional communication channel between human thoughts and the environment. The efficacy of such a BCI depends mainly on the transmitted information rate. Shannon's communication theory was used to quantify the information rate of BCI data. For this purpose, experimental EEG data from four BCI experiments was analyzed off-line. Subjects imaginated left and right hand movements during EEG recording from the sensorimotor area. Adaptive autoregressive (AAR) parameters were used as features of single trial EEG and classified with linear discriminant analysis. The intra-trial variation as well as the inter-trial variability, the signal-to-noise ratio, the entropy of information, and the information rate were estimated. The entropy difference was used as a measure of the separability of two classes of EEG patterns.

Definitive evidence for cuticular pheromones in a cricket

The Orthoptera include many species established as important model systems in the study of animal behaviour, particularly in relation to communication and mating systems. Although most interest has focused on auditory communication, increasing circumstantial evidence suggests that there may be a widespread additional communication channel in the form of cuticular contact pheromones. Using the field cricket,Gryllus bimaculatuswe conducted a behavioural assay which demonstrated that males can distinguish the sex of conspecifics using such a channel. Male response to females (courtship song) was completely abolished by using an organic solvent to remove cuticular hydrocarbons and associated compounds from a stimulus female. It was subsequently restored by painting the washed female with the dissolved extract. This technique controls for the possibility, inherent in previous tests, that the lack of response to washed body parts might be due to the washing process itself. The composition of the cuticles of males and females was analysed using gas chromatography. This revealed that the two sexes differ markedly in the quantities of the majority of the compounds found in the cuticular extract that had previously been shown to be used in mate recognition. This suggests that mate recognition is likely to be due to the relative concentrations of several cuticular compounds, rather than a single ‘sex pheromone’. It supports previous assertions of the existence of contact pheromones in the Orthoptera, suggesting that they may be widespread in this group.

The Effects of Visibility on Dialogue and Performance in a Cooperative Problem Solving Task

This study compares task outcome and various dialogue parameters between situations in which task participants either could or could not see each other. The results establish that the visibility of one's conversational partner improves information transfer and the management of turn taking in a transactional problem solving task. The greater efficiency of the dialogues between participants who could see each other was attributed to the exchange of visually transmitted, non-verbal signals. attempting to compensate for the lack of this additional channel of communication, pairs of subjects who could not see each other demonstrated flexibility and versatility in communicating. They interrupted their partners more frequently and used more back channel responses to provide their partners with increased verbal feedback. The analysis of one specific non-verbal behaviour, gaze, for a subsample of the dialogues, suggested that gaze plays a role in aiding communication.

A communication channel modeled on contagion

We introduce a binary additive communication channel with memory. The noise process of the channel is generated according to the contagion model of G. Polya (1923); our motivation is the empirical observation of Stapper et al. (1980) that defects in semiconductor memories are well described by distributions derived from Polya's urn scheme. The resulting channel is stationary but not ergodic, and it has many interesting properties. We first derive a maximum likelihood (ML) decoding algorithm for the channel; it turns out that ML decoding is equivalent to decoding a received vector onto either the closest codeword or the codeword that is farthest away, depending on whether an apparent epidemic has occurred. We next show that the Polya-contagion channel is an averaged channel in the sense of Ahlswede (1968) and others and that its capacity is zero. Finally, we consider a finite-memory version of he Polya-contagion model; this channel is (unlike the original) ergodic with a nonzero capacity that increases with increasing memory. >

Synchronizable test sequence generation using UIO sequences

This study addresses the synchronization problem that arises during the application of a predetermined test sequence in some protocol test architectures that utilize remote testers. This problem can usually be solved by coordinating the actions of the remote testers using a test management protocol, a ferry protocol with inter-process communication, or a telephone/terminal connection. However, these solutions either require an additional communication channel or an additional protocol for coordination between the testers. Such requirements can be eliminated by constructing a synchronizable test sequence such that the corresponding sequence of transitions causes no synchronization problem. A heuristic we develop in this study constructs a synchronizable test sequence from a given strongly biconnected digraph representing a deterministic and minimal FSM using synchronizable UIO sequences for each state of the given FSM.

Disaster Gipsies: The Role of Informal Relationships in Administering Disaster Assistance

The importance of interpersonal relationships for affecting the efficiency and effectiveness of emergency management practices is examined in this paper. A case study of FEMA (Federal Emergency Management Agency) reservists, part time FEMA employees called to kelp administer federal disaster assistance programs, illustrates the significance of an informal organization in augmenting formal bureaucratic procedures. Interview and survey data come from a pilot study conducted in the aftermath of tornadoes which swept through North and South Carolina in 1984. Nicknamed “disaster gypsies,” FEMA reservists develop a strong sense of community or camaraderie among themselves as a result of their intense disaster involvement. This sense of community or informal organization is an unintended consequence of four factors: organizational demands, physical setting, sense of mission and a post-disaster altruistic community. The informal organization has implications for emergency management practices. It facilitates needed organizational flexibility and improvisation, helps train and integrate new personnel, provides an additional channel of communication and lessens job related stress. Future research should systematically examine the role informal relationahips have on affecting delivery of emergency services. Such research would complement and provide a missing dimension to present efforts to conceptualize group and organizational emergence.

The Application of Western Union Multiplex to Navy Radio

At the beginning of and during the war with Japan, the wide expansion of operations in the Pacific Theater over-taxed the Navy's radio communications to a point where the need of additional communication channels became acute. The adaptation of a 4-channel Western Union type multiplex to a single-channel frequency-shift radio system appeared to be the most logical way to solve this problem quickly. Improvements in the radio and the use of the multiplex enabled the Navy to set up communication channels between the United States and all the principal naval bases in the Pacific. A 4-channel circuit was established between Washington, D. C., and Honolulu, T. H., and San Francisco, Calif., and Honolulu within approximately nine months after the beginning of initial tests. Other systems followed in close succession.