Multi-component Communication Research Articles

Models of Chemical Communication for Micro/Nanoparticles.

ConspectusEngineering chemical communication between micro/nanosystems (via the exchange of chemical messengers) is receiving increasing attention from the scientific community. Although a number of micro- and nanodevices (e.g., drug carriers, sensors, and artificial cells) have been developed in the last decades, engineering communication at the micro/nanoscale is a recent emergent topic. In fact, most of the studies in this research area have been published within the last 10 years. Inspired by nature─where information is exchanged by means of molecules─the development of chemical communication strategies holds wide implications as it may provide breakthroughs in many areas including nanotechnology, artificial cell research, biomedicine, biotechnology, and ICT. Published examples rely on nanotechnology and synthetic biology for the creation of micro- and nanodevices that can communicate. Communication enables the construction of new complex systems capable of performing advanced coordinated tasks that go beyond those carried out by individual entities. In addition, the possibility to communicate between synthetic and living systems can further advance our understanding of biochemical processes and provide completely new tailored therapeutic and diagnostic strategies, ways to tune cellular behavior, and new biotechnological tools. In this Account, we summarize advances by our laboratories (and others) in the engineering of chemical communication of micro- and nanoparticles. This Account is structured to provide researchers from different fields with general strategies and common ground for the rational design of future communication networks at the micro/nanoscale. First, we cover the basis of and describe enabling technologies to engineer particles with communication capabilities. Next, we rationalize general models of chemical communication. These models vary from simple linear communication (transmission of information between two points) to more complex pathways such as interactive communication and multicomponent communication (involving several entities). Using illustrative experimental designs, we demonstrate the realization of these models which involve communication not only between engineered micro/nanoparticles but also between particles and living systems. Finally, we discuss the current state of the topic and the future challenges to be addressed.

ADVANCE CARE PLANNING IN PRIMARY CARE: ENGAGING ACCOMPANIED OLDER ADULTS WITH COGNITIVE IMPAIRMENT

Abstract Alzheimer’s Disease and Related Dementias (ADRD) are among the most profoundly disabling and costly of all health conditions, and persons living with dementia are at heightened risk for high utilization of burdensome and costly end-of-life care. Family caregivers are at the forefront of managing ADRD, however, they are not routinely engaged in primary care discussions about prognosis and the healthcare preferences of the people for whom they care. Advance care planning (ACP) is a longitudinal communication process that supports adults at any age or stage of health in understanding and sharing their personal values, life goals, and preferences regarding future medical care. Early initiation of ACP, communication with the primary care team, and the inclusion of associated caregivers is imperative in ADRD care due to progressive and devastating effects on decision-making capacity connected with the disease. SHARE, a multicomponent communication intervention, engaged 273 patient-family caregiver dyads in a randomized-controlled trial collecting baseline and six-month survey data related to experiences in the primary care setting. 145 patient-caregiver dyads assigned to the intervention received an offer for a facilitated advance care planning conversation. This symposium will highlight 6-month outcomes from caregiver-reported surveys. Attendees will gain a perspective on ACP considerations in a cognitively impaired population including ethical considerations and the factors influencing preparedness for medical decision making for involved family caregivers. Additional attention concerning the quality and content of ACP conversations with patient-caregiver dyads and the development of a fidelity tool for usage with audio-recorded ACP conversations will be presented.

EXPLORATION OF PREPAREDNESS FOR MEDICAL DECISION MAKING FOR FAMILY CAREGIVERS OF PEOPLE WITH DEMENTIA

Abstract As dementia progresses, many family caregivers of people with dementia (PWD) often experience increasing demands of making medical decisions for their loved ones and feel unprepared, causing severe psychological distress. This presentation explores what factors influence preparedness level of family caregivers in medical decision-making for PWD. As part of a larger two-group randomized trial in which 273 PWD-family caregiver dyads received either a control protocol or a multi-component communication intervention including advance care planning (ACP) facilitation, this qualitative study used thematic analysis methods to analyze 10 transcripts resulting from audio-recorded and transcribed ACP conversations with an ACP facilitator, PWD, and family caregivers. Interview duration was over 30 minutes. The major themes identified were: (1) knowledge about PWD’s treatment preferences, (2) experience with death and dying, (3) previous decision-making involvement, and (4) spiritual beliefs. Many family caregivers found ACP conversations with PWD about their goals of care to be beneficial in improving their confidence in making medical decisions. A few participants also reported witnessing a loved one’s suffering at the end of life or having made care decisions for family before helped them to initiate conversations with PWD about medical wishes, thus enhanced readiness for decision making. Lastly, few caregivers reported belief in God would help them make the “right decisions”. Preliminary results highlight that caregivers’ understanding of PWD’s treatment preferences helps to prepare family caregivers for decision-making, underlining the need for early and culturally appropriate ACP conversations among residents, caregivers, and clinicians.

Sharing Health Care Wishes in Primary Care (SHARE) among older adults with possible cognitive impairment in primary care: Study protocol for a randomized controlled trial

ObjectiveLittle is known about effective strategies to improve advance care planning (ACP) for persons with cognitive impairment in primary care, the most common setting of care. We describe a randomized controlled trial to test the efficacy of a multicomponent communication intervention, “Sharing Healthcare Wishes in Primary Care” (SHARE). ParticipantsPlanned enrollment of 248 dyads of adults 80 years and older with possible cognitive impairment and their care partner, from primary care clinics at 2 Mid-Atlantic health systems. MethodsThe treatment protocol encompasses an introductory letter from the clinic; access to a designated facilitator trained in ACP; person-family agenda-setting to align perspectives about the family's role; and print education. The control protocol encompasses minimally enhanced usual care, which includes print education and a blank advance directive. Randomization occurs at the individual dyad-level. Patient and care partner surveys are fielded at baseline, 6-, 12-, and 24- months. Fidelity of interventionist delivery of the protocol is measured through audio-recordings of ACP conversations and post-meeting reports, and by ongoing monitoring and support of interventionists. OutcomesThe primary outcome is quality of end-of-life care communication at 6 months; secondary outcomes include ACP process measures. An exploratory aim examines end-of-life care quality and bereaved care partner experiences for patients who die by 24 months. ConclusionsCaregiver burden, clinician barriers, and impaired decisional capacity amplify the difficulty and importance of ACP discussions in the context of cognitive impairment: this intervention will comprehensively examine communication processes for this special subpopulation in a key setting of primary care.Registration: ClinicalTrials.gov: NCT04593472.

Cut and Forward: Safe and Secure Communication for FPGA System on Chips

Modern FPGA system on chips uses complex multimanager, multisubordinate on-chip communication networks. Processor cores, hardware accelerators, DMA engines, and other manager components actively access subordinate components like off-chip DRAM, on-chip memories, caches, and I/Os. On-chip communication networks are designed for high bandwidth and low latency. They use simple, fast transactions that largely assumes the managers cooperate. For example, it does not describe default mechanisms to ensure the safe behaviors of the managers using the on-chip interconnect. This lack of specification can lead to unpredictable behaviors: a single misbehaving, misconfigured, or malicious component can cause denial of service of shared resources. Clearly, this issue is critical in systems with safety and security constraints. Cut and forward is a novel switching method for multicomponent communication architectures on FPGA systems on chips (SoCs). Cut and forward leverages the programmability of FPGA SoCs to enable safe and secure bus access and is carefully designed to minimize its impact on performance and resource usage. Experiments show that Cut and forward ensures safety and security in realistic applications deployed on a commercial FPGA SoC from Xilinx including a popular deep neural network accelerator.

The face is central to primate multicomponent signals

AbstractA wealth of experimental and observational evidence suggests that faces have become increasingly important in the communication system of primates over evolutionary time and that both the static and moveable aspects of faces convey considerable information. Therefore, whenever there is a visual component to any multicomponent signal the face is potentially relevant. However, the role of the face is not always considered in primate multicomponent communication research. We review the literature and make a case for greater focus on the face going forward. We propose that the face can be overlooked for two main reasons: first, due to methodological difficulty. Examination of multicomponent signals in primates is difficult, so scientists tend to examine a limited number of signals in combination. Detailed examination of the subtle and dynamic components of facial signals is particularly hard to achieve in studies of primates. Second, due to a common assumption that the face contains “emotional” content. A priori categorisation of facial behavior as “emotional” ignores the potentially communicative and predictive information present in the face that might contribute to signals. In short, we argue that the face is central to multicomponent signals (and also many multimodal signals) and suggest future directions for investigating this phenomenon.

A multicomponent intervention to optimise nurse–patient communication in the intensive care unit: A mixed-methods acceptability and feasibility study

BackgroundMechanically ventilated patients in intensive care units may experience communication challenges owing to intubation, which affects nurse–patient communication. Several strategies may optimise communication, but only one previous study has tested a multicomponent intervention. Implementing such an intervention can be challenging because communication strategies may be set aside by lifesaving care tasks and procedures. In a previous study, we designed a communication intervention based on pre-existing clinical methods and evidence-based approaches. The present study evaluated the intervention to determine if it was necessary to adjust its components and the implementation strategy. ObjectivesThe objective of this study was to evaluate the feasibility and assess nurses’ acceptability of a patient-centred, multicomponent communication intervention prototype in an intensive care unit. MethodsThe overall frame was the Medical Research Council's framework for developing complex interventions. Indicators of feasibility and acceptability were used for the evaluation. A mixed-methods design was applied including a survey with open-ended text boxes and qualitative observations as data sources. Quantitative data were analysed descriptively, and qualitative data were explored using content analysis. Data were compiled and displayed in a side-by-side comparison. The data were collected between September 2020 and March 2021. Nurses from four intensive care units at a university hospital in Denmark participated in the study. All nurses who were on active duty during the implementation of the intervention were enrolled for the survey and participant observations. ResultsOverall, the results provided insight into the feasibility based on fidelity and context as well as nurses’ acceptability based on adherence, appropriateness, convenience, and effectiveness. Qualitative and quantitative results yielded partially contrasting findings but highlighted how the intervention may be optimised to enhance fit with clinical practice and overcome implementation challenges. ConclusionThe intervention was feasible and acceptable. However, implementation needs to be repeated to allow nurses to fully understand and use the intervention.

Non-Concordance between Patient and Clinician Estimates of Prognosis in Advanced Heart Failure

Despite efforts to enhance serious illness communication, patients with advanced heart failure (HF) lack prognostic understanding. To determine rate of concordance between HF patients' estimation of their prognosis and their physician's estimate of the patient's prognosis, and to compare patient characteristics associated with concordance. Cross-sectional analysis of a cluster randomized controlled trial with 24-month follow-up and analysis completed on 09/01/2020. Patients were enrolled in inpatient and outpatient settings between September 2011 to February 2016 and data collection continued until the last quarter of 2017. Six teaching hospitals in the U.S. Patients with advanced HF and implantable cardioverter defibrillators (ICDs) at high risk of death. Of 537 patients in the parent study, 407 had complete data for this analysis. A multi-component communication intervention on conversations between HF clinicians and their patients regarding ICD deactivation and advance care planning. Patient self-report of prognosis and physician response to the "surprise question" of 12-month prognosis. Patient-physician prognostic concordance (PPPC) measured in percentage agreement and kappa. Bivariate analyses of characteristics of patients with and without PPPC. Among 407 patients (mean age 62.1 years, 29.5% female, 42.4% non-white), 300 (73.7%) dyads had non-PPPC; of which 252 (84.0%) reported a prognosis >1 year when their physician estimated <1 year. Only 107 (26.3%) had PPPC with prognosis of ≤ 1 year (n=20 patients) or > 1 year (n=87 patients); (Κ = -0.20, p = 1.0). Of those with physician estimated prognosis of < 1 year, non-PPPC was more likely among patients with lower symptom burden- number and severity (both p ≤.001), without completed advance directive (p=.001). Among those with physician prognosis estimate > 1 year, no patient characteristic was associated with PPPC or non-PPPC. Non-PPPC between HF patients and their physicians is high. HF patients are more optimistic than clinicians in estimating life expectancy. These data demonstrate there are opportunities to improve the quality of prognosis disclosure between patients with advanced HF and their physicians. Interventions to improve PPPC might include serious illness communication training.

Strengthening and supporting nurses' communication with mechanically ventilated patients in the intensive care unit: Development of a communication intervention.

Nurse-patient communication in intensive care units is challenged by the fact that patients are voiceless due to intubation and mechanical ventilation. Difficult communication affects nurses negatively, and it requires knowledge and expertise to facilitate communication in this complex and technologically tense setting. Augmentative and alternative communication has been suggested as a way of optimising communication; several approaches can be combined in a multi-component intervention. Also, a communication algorithm has been proposed as a way of providing structure in patient communication. To enhance transparency and avoid poorly reported interventions, this paper describes the process, rationale and reflections behind developing a communication intervention called the ICU-COM. To present the development process of a communication intervention prototype that aims to support and strengthen nurses' communication with mechanically ventilated patients in an intensive care unit. The Medical Research Council's framework for developing complex interventions in health was applied. The approach was target-population centred. The intervention was developed and tailored to four intensive care unit departments at Aarhus University Hospital in Denmark. Intensive care nurses and various experts, namely, speech-language pathologists, graphic designers, a software company, the local Centre for E-learning and nurse specialists were involved in its development. An intervention consisting of: 1) a multi-component communication bundle, 2) delivery of the bundle via a teaching session and 3) initial implementation via nurse communication guides was developed. The communication bundle contained: 1) a communication strategy with a BASIS framework and algorithm, 2) a nurse education programme and 3) low-tech and high-tech communication tools. A systematic approach was applied in the development process. However, the acceptability and feasibility of the intervention is at present unknown.

Nurses’ experiences of serving as a communication guide and supporting the implementation of a communication intervention in the intensive care unit

ABSTRACT Purpose : To explore the experience of serving as a nurse communication guide, supporting the bottom-up implementation of a multi-component communication intervention prototype in the intensive care unit. Methods : The overall frame was Complex Interventions, and the study was conducted within the phenomenological-hermeneutic tradition. Semi-structured telephone interviews were conducted with eight nurse communication guides. Data were analysed using a Ricoeur-inspired interpretation method. Results : Two main themes emerged: 1) “The communication intervention components provided overview, a conceptual framework, awareness and room for reflection” and 2) “Being a communication guide illuminated the barriers and challenges of implementation”. Furthermore, a comprehensive understanding was established that illuminated experiences throughout the analysis: “An ICU communication intervention has to be adaptable to the specific situation and the double need for individualization but also provide overall guidance”. Conclusion : Findings showed that as communication is inherent to all human beings, it can be difficult to change the communication behaviour of nurses. Therefore, a communication intervention in the intensive care unit must be sensitive to the nurse communication guides’ individual communication style. Furthermore, a communication intervention should provide nurse communication guides with overall guidance while at the same time remaining adaptable to the needs of each specific situation.

The relationship between a combinatorial processing rule and a continuous mate preference function in an insect.

Mate choice involves processing signals that can reach high levels of complexity and feature multiple components, even in small animals with tiny brains. This raises the question of whether and how such organisms deal with this complexity. One solution involves combinatorial processing, whereby different signal elements are processed as single units. Combinatorial processing has been described in several mammals and birds, and recently in a vibrationally signalling insect, Enchenopa treehoppers. Here, we ask about the relationship between combinatorial rules and mate preferences for continuously varying signal features. Enchenopa male advertisement signals are composed of two elements: a 'whine' followed by a set of pulses. The dominant frequency of the whine and element combination both matter to females. We presented synthetic signals varying in element order (natural [whine-pulses], reverse [pulses-whine]) and in frequency to Enchenopa females and recorded their responses. The reverse combination resulted in a decrease in attractiveness of the signals, and also slightly changed the shape of the preference for frequency. We found that females could be classified into three 'types': females with both a strong preference and a strong combinatorial rule, females with both a weak preference and weak rule, and females with a strong preference but a weak rule. Our results suggest that in Enchenopa signal processing, the mate preference for a continuous signal feature 'takes precedence' over, but also interacts with, the combinatorial rule. The relationship between the preference and the rule could evolve to take different forms according to selection on mate choice decisions. We suggest that exploring the relationship between such preferences and rules in species with more complex signals will bring insight into the evolution of the multi-component communication systems.

Multi-component communication intervention for children with autism: A randomized controlled trial.

This study reports the results of a randomized trial for preverbal preschoolers with autism that demonstrates the effects of multiple intervention strategies including caregiver training. About 50% of children with autism are not talking by age 3 and up to 30% of children with autism will remain minimally verbal past age 5. Interventions delivered by clinicians and caregivers have the greatest effects on spoken language and may reduce the rate of those who remain minimally verbal. Sixty-eight children ages 3-5 with autism and their caregivers participated in this randomized trial comparing the communication intervention to a comparison group. A brief, multi-component, communication intervention (including a speech-generating device) for children with autism that addresses core deficits may be effective in improving joint attention skills immediately following intervention and social communication skills 4 months following intervention. Future research is needed to understand for whom and under what conditions this intervention is most effective.

Use of Important Measure Factors for Evaluating the Contribution of Individual Components to the Performance of Critical Systems

Abstract The purpose of this paper is to provide an analysis tool for computing the risk of complex systems according to some Importance Measure Concepts (IMC) in such a way that the results of the computation are displayed in terms of a list of preference which classifies the components according to their IMC values. From this list, one can determine the risk amplitude and take the necessary decisions for making the system less risky, safer and robust. We have tested the effectiveness of these IMC’s using a case study of a multicomponent communication system.

Nonlinear processing of a multicomponent communication signal by combination-sensitive neurons in the anuran inferior colliculus.

Diverse animals communicate using multicomponent signals. How a receiver's central nervous system integrates multiple signal components remains largely unknown. We investigated how female green treefrogs (Hyla cinerea) integrate the multiple spectral components present in male advertisement calls. Typical calls have a bimodal spectrum consisting of formant-like low-frequency (~0.9kHz) and high-frequency (~2.7kHz) components that are transduced by different sensory organs in the inner ear. In behavioral experiments, only bimodal calls reliably elicited phonotaxis in no-choice tests, and they were selectively chosen over unimodal calls in two-alternative choice tests. Single neurons in the inferior colliculus of awake, passively listening subjects were classified as combination-insensitive units (27.9%) or combination-sensitive units (72.1%) based on patterns of relative responses to the same bimodal and unimodal calls. Combination-insensitive units responded similarly to the bimodal call and one or both unimodal calls. In contrast, combination-sensitive units exhibited both linear responses (i.e., linear summation) and, more commonly, nonlinear responses (e.g., facilitation, compressive summation, or suppression) to the spectral combination in the bimodal call. These results are consistent with the hypothesis that nonlinearities play potentially critical roles in spectral integration and in the neural processing of multicomponent communication signals.

Can we improve the quality of documented end-of-life conversations using a structured, multicomponent intervention?

49 Background: Conversations about serious illness care goals are often inadequate and fail to address key elements of high-quality discussions. Methods: As part of a cluster-randomized trial of a multi-component communication intervention, we conducted a retrospective chart review of 147 deceased oncology patients to assess frequency and timing of documentation of end-of-life (EOL) conversations; charts of a subset of 20 intervention and 20 matched control patients underwent detailed review to assess quality. A systematically developed abstraction tool was used by two blinded researchers. The tool contained 25 elements reflecting four EOL conversation domains: goals/values, illness understanding/prognosis, EOL care planning, life-sustaining treatments. Results: Of 153 intervention patients, 44.4% died (n = 68); of 161 controls, 49.1% died (n = 79). Significantly more intervention patients than controls (92.7% vs 74.7%, p = 0.006) had at least 1 documented EOL discussion before death; intervention conversations occurred 3 months earlier (median 147 days vs 62 days, p = 0.003). 59.4% of intervention conversations were documented in a retrievable EHR location compared to 10.2% of controls (p = 0.001). In the detailed review, 85% (n = 17) of intervention and 40% (n = 8) of controls had at least 1 documented discussion about values/goals (p = 0.0001), with an average of 3.6 of 8 elements (0.7 of 8 for controls) (p = 0.0003). 85% percent (n = 17) of intervention and 30% (n = 6) of controls had at least 1 documented discussion about prognosis (p = 0.0014), with an average of 2.5 of 7 elements (0.5 of 7 for controls) (p = 0.001). 85% of intervention (n = 17) and 55% of controls (n = 11) had at least 1 documented discussion about EOL planning (p = 0.009). 55% of intervention and 30% of controls had at least 1 documented discussion about life-sustaining treatments (p = 0.20). Conclusions: The intervention resulted in more, earlier and better documentation of serious illness care goals. Across 3 of 4 domains of quality, intervention patients had more detailed information about their EOL care preferences, demonstrating that the intervention results in more patient-centered, comprehensive discussions. Clinical trial information: NCT01786811.

Read-B4-U-Eat: A Multicomponent Communication Module to Promote Food Label Reading Skills Among Adolescents in India

India is home to about 20% of the world's adolescent population, 1 The state of world's children 2011. UNICEF. http://www.unicef.org/sowc2011/pdfs/SOWC-2011-Main-Reportchapter-2_12082010.pdf. Accessed June 22, 2016. Google Scholar over 10% of whom are overweight or obese. 2 Wang Y. Chen H.J. Shaikh S. Mathur P. Is obesity becoming a public health problem in India? Examine the shift from under- to over-nutrition problems over time. Obes Rev. 2009; 10: 456-474 Crossref PubMed Scopus (132) Google Scholar Curbing adolescent obesity, a reason for the onset of adult chronic diseases, has become an important public health priority. The increased availability of processed and prepackaged foods and the increase in consumption of away-from-home foods compared with at-home foods, coupled with limited nutrition literacy and an inability to interpret caloric and nutrient information affect food choices. 3 Gavaravarapu S.M. Vemula S.R. Rao P. Rao M.V. Polasa K. Focus group studies on food safety knowledge, perceptions, and practices of school-going adolescent girls in South India. J Nutr Educ Behav. 2009; 41: 340-346 Abstract Full Text Full Text PDF PubMed Scopus (37) Google Scholar , 4 Gavaravarapu S.M. Rao K.M. Nagalla B. Avula L. Assessing differences in risk perceptions about obesity among “normal-weight” and “overweight” adolescents—a qualitative study. J Nutr Educ Behav. 2015; 47: 488-497 Abstract Full Text Full Text PDF PubMed Scopus (12) Google Scholar Previous studies have shown that adolescents consider food labels to be a good source of information but they often find the information confusing or too technical. 5 Vemula S.R. Gavaravarapu S.M. Mendu V.V.R. Mathur P. Avula L. Use of food label information by urban consumers in India—a study among supermarket shoppers. Public Health Nutr. 2014; 17: 2104-2114 Crossref PubMed Scopus (33) Google Scholar , 6 Saha S. Vemula S.R. Mendu V.V.R. Gavaravarapu S.M. Knowledge and practices of using food label information among adolescents attending schools in Kolkata, India. J Nutr Educ Behav. 2013; 45: 773-779 Abstract Full Text Full Text PDF PubMed Scopus (28) Google Scholar Adolescents prefer to learn about nutrition and label reading in school settings when it is integrated into school curricula. 3 Gavaravarapu S.M. Vemula S.R. Rao P. Rao M.V. Polasa K. Focus group studies on food safety knowledge, perceptions, and practices of school-going adolescent girls in South India. J Nutr Educ Behav. 2009; 41: 340-346 Abstract Full Text Full Text PDF PubMed Scopus (37) Google Scholar , 6 Saha S. Vemula S.R. Mendu V.V.R. Gavaravarapu S.M. Knowledge and practices of using food label information among adolescents attending schools in Kolkata, India. J Nutr Educ Behav. 2013; 45: 773-779 Abstract Full Text Full Text PDF PubMed Scopus (28) Google Scholar Because school was considered to be an effective platform to reach adolescents, a multicomponent communication module called READ-B4-U-EAT (Read Before You Eat) was developed to promote the use of food label information and informed food choices. The current article assesses the impact of the READ-B4-U-EAT communication module on knowledge and self-reported practices related to the use of food label information among adolescents.

Communication, ideation and contraceptive use in Burkina Faso: an application of the propensity score matching method

ObjectiveThe study aim was to assess the effects of a multi-component communication campaign that promoted contraceptive use in Burkina Faso.MethodsThis was a cross-sectional survey conducted in 2001 involving 1421 women...

Influenza pandemic preparedness plan for the United States.

In preparation for the next influenza pandemic, a comprehensive and action-oriented plan is presently under development that focuses on six major areas: (1) improvements in ongoing virologic and disease-based surveillance systems; (2) vaccination of high-priority target groups, and, given sufficient vaccine supplies, the entire US population; (3) liability programs for vaccine manufacturers and health care providers; (4) research to improve detection of new variants and to accelerate the availability of existing and novel vaccines and antiviral agents; (5) integrated, multicomponent communication systems for rapid information dissemination and exchange; and (6) emergency preparedness plans to provide for adequate medical care and maintenance of essential community services. The sudden and unpredictable emergence of pandemic influenza and its potential for causing severe health and social consequences dictate the need for close collaboration among a wide variety of organizations in both the public and private sectors.

Traffic modelling for packet communication networks

A general model for the description of traffic processes in packet communication networks is presented in this paper. The packet traffic generated by a network component is described in terms of a generalized Bernoulli process whose intensity depends on the state of the component. When the state space of the component is large, an approximate traffic characterization is proposed based on the dominant states. The latter characterization is shown to be well performing for the considered examples of practical network components. Based on the proposed general model, an analysis approach for multi-component communication networks is presented. Numerical results illustrate the inaccuracy of the widely adopted i.i.d. modelling, the effectiveness of the proposed general model and the significant complexity reduction through the adoption of the approximate one.