Loss fluctuations and temporal correlations in network queues

We consider data losses in a single node of a packet- switched Internet-like network. We employ two distinct models, one with discrete and the other with continuous one-dimensional random walks, representing the state of a queue in a router. Both models have a built-in critical behavior with a sharp transition from exponentially small to finite losses. It turns out that the finite capacity of a buffer and the packet-dropping procedure give rise to specific boundary conditions which lead to strong loss rate fluctuations at the critical point even in the absence of such fluctuations in the data arrival process.

From practice to field:a multi-level model of practice-driven institutional change

This article develops a model of practice-driven institutional change - or change that originates in the everyday work of individuals but results in a shift in field-level logic. In demonstrating how improvisations at work can generate institutional change, we attend to the earliest moments of change, which extant research has neglected; and we contrast existing accounts that focus on active entrepreneurship and the contested nature of change. We outline the specific mechanisms by which change emerges from everyday work, becomes justified, and diffuses within an organization and field, as well as precipitating and enabling dynamics that trigger and condition these mechanisms. © Academy of Management Journal.

Innovation, networking and globalisation:the role of regional innovation systems in the global innovation process

In the global economy, innovation is one of the most important competitive assets for companies willing to compete in international markets. As competition moves from standardised products to customised ones, depending on each specific market needs, economies of scale are not anymore the only winning strategy. Innovation requires firms to establish processes to acquire and absorb new knowledge, leading to the recent theory of Open Innovation. Knowledge sharing and acquisition happens when firms are embedded in networks with other firms, university, institutions and many other economic actors. Several typologies of innovation and firm networks have been identified, with various geographical spans. One of the first being modelled was the Industrial Cluster (or in Italian Distretto Industriale) which was for long considered the benchmark for innovation and economic development. Other kind of networks have been modelled since the late 1970s; Regional Innovation Systems represent one of the latest and more diffuse model of innovation networks, specifically introduced to combine local networks and the global economy. This model was qualitatively exploited since its introduction, but, together with National Innovation Systems, is among the most inspiring for policy makers and is often cited by them, not always properly. The aim of this research is to setup an econometric model describing Regional Innovation Systems, becoming one the first attempts to test and enhance this theory with a quantitative approach. A dataset of 104 secondary and primary data from European regions was built in order to run a multiple linear regression, testing if Regional Innovation Systems are really correlated to regional innovation and regional innovation in cooperation with foreign partners. Furthermore, an exploratory multiple linear regression was performed to verify which variables, among those describing a Regional Innovation Systems, are the most significant for innovating, alone or with foreign partners. Furthermore, the effectiveness of present innovation policies has been tested based on the findings of the econometric model. The developed model confirmed the role of Regional Innovation Systems for creating innovation even in cooperation with international partners: this represents one of the firsts quantitative confirmation of a theory previously based on qualitative models only. Furthermore the results of this model confirmed a minor influence of National Innovation Systems: comparing the analysis of existing innovation policies, both at regional and national level, to our findings, emerged the need for potential a pivotal change in the direction currently followed by policy makers. Last, while confirming the role of the presence a learning environment in a region and the catalyst role of regional administration, this research offers a potential new perspective for the whole private sector in creating a Regional Innovation System.

Balance and gait in children with dyslexia

Tests of postural stability have provided some evidence of a link between deficits in gross motor skills and developmental dyslexia. The ordinal-level scales used previously, however, have limited measurement sensitivity, and no studies have investigated motor performance during walking in participants with dyslexia. The purpose of this study was to investigate if continuous-scaled measures of standing balance and gait could discriminate between groups of impaired and normal readers when investigators were blind to group membership during testing. Children with dyslexia (n=22) and controls (n=18), aged 10-12 years, performed walking tests at four different speeds (slow-preferred-fast-very fast) on an even and an uneven surface, and tests of unperturbed and perturbed body sway during standing. Body movements were registered by a triaxial accelerometer over the lower trunk, and measures of reaction time, body sway, walking speed, step length and cadence were calculated. Results were controlled for gender differences. Tests of standing balance with eyes closed did not discriminate between groups. All unperturbed standing tests with eyes open showed significant group differences (P<0.05) and classified correctly 70-77.5% of the subjects into their respective groups. Mean walking speed during very fast walking on both flat and uneven surface was ≥0.2 m/s (P≤0.01) faster for controls than for the group with dyslexia. This test classified 77.5% and 85% of the subjects correctly on flat and uneven surface, respectively Cadence at preferred or very fast speed did not differ statistically between groups, but revealed significant group differences when all subjects were compared at a normalised walking speed (P≤0.04). Very fast walking speed as well as cadence at a normalised speed discriminated better between groups when subjects were walking on an uneven surface compared to a flat floor. Continuous-scaled walking tests performed in field settings may be suitable for motor skill assessment as a component of a screening tool for developmental dyslexia.

Using Physical Quantities in Applied Mathematical Problems with Maple

The present article discusses units of measure and their base units, work environments built in the Units package of the computer algebra system Maple. An analysis is drawn of the tools of the application in connection with the use of physical quantities and their features. Maple’s main commands are arranged in groups depending on the function. Some applied mathematical problems are given as examples making use of derivative, integral and differential equations.

Comparative Analysis: A Feasible Software Engineering Method

The reasonable choice is a critical success factor for decision- making in the field of software engineering (SE). A case-driven comparative analysis has been introduced and a procedure for its systematic application has been suggested. The paper describes how the proposed method can be built in a general framework for SE activities. Some examples of experimental versions of the framework are brie y presented.

'There's a hell of a noise':living with a hearing loss in residential care

Background: hearing loss is common in older age. Research with older people in residential care settings has identified high prevalence of hearing loss and low uptake of hearing aids. Hearing loss in these settings is associated with reduced social engagement. Although hearing aids remain the default treatment for presbyacusic hearing loss, these are not well used. We do not know what other modifiable factors contribute to communication problems for older people with hearing loss living in residential care. Objectives: to explore the factors affecting communicating with a hearing loss in residential care. Methods: an ethnographic study in two residential care homes comprised 19 sessions of observation, and in-depth interviews with 18 residents. Observations explored communication behaviour in everyday interactions, including mealtimes, structured groups and informal group activities. Interviews were informed by the observations and identified reasons for these behaviours and communication preferences. Observational data were recorded in field notes and interviews were audio-recorded and transcribed. Analysis was conducted using constant comparison methods. Results: hearing loss affected whether residents were able to access social opportunities. Two key themes influenced this (i) contextual issues compounded communication difficulties and (ii) environmental noise restricted the residents' communication choices. Problems were observed at every mealtime and during formal and informal group activities. The use of hearing aids and access to hearing services did not improve social engagement. Conclusions: environmental and social factors are key to maximising communication opportunities. Improvements to communication in residential care settings could be based on changes in these with input from residents and staff. Further work is needed to develop effective communication strategies in residential care.

Using Covariance as a Similarity Measure for Document Language Identification in Hard Contexts

2000 Mathematics Subject Classification: C2P99.

Optical-phase conjugation nonlinearity compensation in Flexi-Grid optical networks

Optical-phase conjugation nonlinearity compensation (OPC-NLC) in optical networks is evaluated using a built-in tool including self-channel and crosstalk channel interference effects. Though significant improvements are observed, a further refined launch power policy is required to fully take advantage of OPC-NLC capability.

Discovering knowledge structures in mind maps of mental health risks

This thesis addressed the problem of risk analysis in mental healthcare, with respect to the GRiST project at Aston University. That project provides a risk-screening tool based on the knowledge of 46 experts, captured as mind maps that describe relationships between risks and patterns of behavioural cues. Mind mapping, though, fails to impose control over content, and is not considered to formally represent knowledge. In contrast, this thesis treated GRiSTs mind maps as a rich knowledge base in need of refinement; that process drew on existing techniques for designing databases and knowledge bases. Identifying well-defined mind map concepts, though, was hindered by spelling mistakes, and by ambiguity and lack of coverage in the tools used for researching words. A novel use of the Edit Distance overcame those problems, by assessing similarities between mind map texts, and between spelling mistakes and suggested corrections. That algorithm further identified stems, the shortest text string found in related word-forms. As opposed to existing approaches’ reliance on built-in linguistic knowledge, this thesis devised a novel, more flexible text-based technique. An additional tool, Correspondence Analysis, found patterns in word usage that allowed machines to determine likely intended meanings for ambiguous words. Correspondence Analysis further produced clusters of related concepts, which in turn drove the automatic generation of novel mind maps. Such maps underpinned adjuncts to the mind mapping software used by GRiST; one such new facility generated novel mind maps, to reflect the collected expert knowledge on any specified concept. Mind maps from GRiST are stored as XML, which suggested storing them in an XML database. In fact, the entire approach here is ”XML-centric”, in that all stages rely on XML as far as possible. A XML-based query language allows user to retrieve information from the mind map knowledge base. The approach, it was concluded, will prove valuable to mind mapping in general, and to detecting patterns in any type of digital information.

Slow Isotope Turnover Rates and Low Discrimination Values in the American Alligator: Implications for Interpretation of Ectotherm Stable Isotope Data

Stable isotope analysis has become a standard ecological tool for elucidating feeding relationships of organisms and determining food web structure and connectivity. There remain important questions concerning rates at which stable isotope values are incorporated into tissues (turnover rates) and the change in isotope value between a tissue and a food source (discrimination values). These gaps in our understanding necessitate experimental studies to adequately interpret field data. Tissue turnover rates and discrimination values vary among species and have been investigated in a broad array of taxa. However, little attention has been paid to ectothermic top predators in this regard. We quantified the turnover rates and discrimination values for three tissues (scutes, red blood cells, and plasma) in American alligators (Alligator mississippiensis). Plasma turned over faster than scutes or red blood cells, but turnover rates of all three tissues were very slow in comparison to those in endothermic species. Alligator δ15N discrimination values were surprisingly low in comparison to those of other top predators and varied between experimental and control alligators. The variability of δ15N discrimination values highlights the difficulties in using δ15N to assign absolute and possibly even relative trophic levels in field studies. Our results suggest that interpreting stable isotope data based on parameter estimates from other species can be problematic and that large ectothermic tetrapod tissues may be characterized by unique stable isotope dynamics relative to species occupying lower trophic levels and endothermic tetrapods.

A Cross-Generational Analysis of Spanish-to-English Lexico-Semantic Phenomena in Emerging Miami English

Sociolinguists have documented the substrate influence of various languages on the formation of dialects in numerous ethnic-regional setting throughout the United States. This literature shows that while phonological and grammatical influences from other languages may be instantiated as durable dialect features, lexical phenomena often fade over time as ethnolinguistic communities assimilate with contiguous dialect groups. In preliminary investigations of emerging Miami Latino English, we have observed that lexical forms based on Spanish lexical forms are not only ubiquitous among the speech of the first generation Cuban Americans but also of the second. Examples, observed in field work, casual observation, and studied formally in an experimental context include the following: “get down from the car,” which derives from the Spanish equivalent, bajar del carro instead of “get out of the car”. The translation task administered to thirty-one participants showed a variety lexical phenomena are still maintained at equal or higher frequencies.

Estudo do domínio segurança/proteção da NANDA internacional em pacientes de unidade de terapia intensiva

The study aimed to analyze the field of nursing diagnoses safety / protection of NANDA International present in patients in the Intensive Care Unit. This is a crosssectional study in intensive care complex of a university hospital in northeastern Brazil. The research took place in two stages. The first step was to collect data through an interview form and physical examination, with 86 patients admitted to the unit, during the months of December 2013 to May 2014. Spreadsheets were built in Microsoft Office Excel 2010 Software in which were marked by the researcher of this study, the presence or absence of defining characteristics, related factors and risk factors of the 31 studied diagnoses. In the second stage, held between July and August 2014, the sheets were sent to three diagnosticians, previously trained to perform the diagnostic inference. Data were analyzed using descriptive and inferential statistics for the diagnoses that showed higher frequencies than 50%, using IBM SPSS version 20.0 for Statistic Windows.O project was approved by the 440/414 and Presentation Certificate for Ethics Assessment number 22955113 .2.0000.5292. The results indicated the presence of 29 field of nursing diagnoses safety / protection in hospital clientele in the Intensive Care Unit, of which five were present in 100% of patients, namely: Risk of contamination, injury risk, falls risk,risk of allergic response and risk of trauma. Diagnoses that presented more frequently than 50% were: Risk of infection, dry eye risk, poisoning risk, vascular trauma risk, impaired skin integrity, impaired dentition, bleeding risk, risk imbalance in body temperature, Risk perioperative positioning injury, impaired tissue integrity, peripheral neurovascular dysfunction Risk, Risk adverse response to contrast media with iodine, shock Hazard and Risk of aspiration. For these analyzes, we identified 35 risk factors, 11 defining characteristics and three related factors showed statistically significant association with the studied diagnoses. For diagnostics: Risk of contamination, injury risk, falls risk, allergic response risk, trauma Risk, Risk of infection, dry eye risk and risk poisoning there was no association with any of their risk factors. We conclude that most of the area of nursing diagnoses safety / protection feature is prevalent in critically ill patients, with special attention to the risk diagnoses. There was a significant association between these diagnoses and its components. It is noteworthy, therefore, that the lifting of this profile contributes relevant clues to the inference of the priority nursing diagnoses domain safety / protection in the study population, supporting the practice of nursing and stimulating knowledge on the subject.

Análise da atividade cognitiva do operador de sala de controle da produção de controle da produção de petróleo on-shore: uma abordagem da ergonomia para a gestão das restrições do sistema sociotécnico

This master's thesis aims to analyze the activity of the operators in a control room of the processes of production on-shore petroleum, with a focus on sociotechnical restrictions that interfere in the decision-making process and the actions of operators and therefore, the strategies (individual and collective) to regulate and maintain the operator action required and the safety of the system, together. The activity in focus involves the supervision and control of the production of thousands of barrels of oil/day in a complex and dispersed production’s structures built in an extension of 80 km. This operational framework highlights the importance of this activity for the fulfilment of the targets local and corporate efficiency, good management of the environment, health and safety of operators. This is an exploratory research and in the field, which uses the methodology of Ergonomic Analysis of the Work, composed of observational techniques and interactional, having as locus control room of the processes of production on-shore oil of an oil company. The population of this research is formed by operators in the control room of an Brazilian oil company. The results showed that the supervisory activity and control of the superheated steam injection is an complex context, demands greater attention, concentration, calculations, comparisons, trend analysis and decision making. The activity is collectively constructed between the control room operator, field operator and the supplier of steam. The research showed that the processes of communication and collaboration between the control room , fields and support staff are the key elements of this activity. The study shows that the operators have the autonomy and the elements necessary for work; and that there is continuous investments to improve the technology used and that the operators report sleep disturbances as a result of chronic exposure to night work. The study contributed with proposals for transformation of this activity: with regard to the installation of a area reserved for food in control room, the update the screens of the supervisory current operating condition, the periodic visits by room operators in the field, standardization of production reports, development assistance and standardization of nomenclature of controlling stations steam systems, to improve the conditions of realization of the activity, improve the quality of products produced by operators and contribute to reduce the possibility of slips or shifts in the activity.

Uma estratégia para otimizar a geração de arranjos em subestações virtuais de energia elétrica

The Virtual Reality techniques applied in Electricity Environments provide a new supervisory control paradigm. The fact of existing a virtual environment (VE), geometrically similar to a real substation, reduces the difference of mental models built by field operators compared with those built by system center operation improving the communication. Beside this, those systems can be used as visualization interfaces for electricity system simulators, training systems for professors and undergraduate students, field operators and maintenance professionals. However, the development process of these systems is quite complex, combining several activities such as implementation, 3D modeling, virtual sceneries construction, usability assessment and management project techniques. In this context, this work present a GUI strategy to build field arrangements based on scene graphs, to reduce time in Virtual Electricity Substations Arrangement development. Through this, mistakes during the VE building can be avoided making this process more reliable. As an concept proof, all toolkits developed in this work were applied in the virtualization of the substations from a Brazilian power concessionary named CEMIG.