Rogers Model Research Articles

An Innovative Approach to the Development of an International Software Process Lifecycle Standard for Very Small Entities

For very small software development companies, the quality of their software products is a key to competitive advantage. However, the usage of Software Engineering standards is extremely low amongst such very small software companies. A primary reason cited by many such companies for this lack of quality standards adoption is the perception that they have been developed for large multi-national software companies and not with small and very small organizations in mind and are therefore not suitable for their specific needs. This paper describes an innovative systematic approach to the development of the software process lifecycle standard for very small entities ISO/IEC 29110, following the Rogers model of the Innovation-Development process. The ISO/IEC 29110 standard is unique amongst software and systems engineering standards, in that the working group mandated to develop a new standard approached industry to conduct a needs assessment and gather actual requirements for a new standard as part of the standards development process. This paper presents a unique insight from the perspective of some of the standards authors on the development of the ISO/IEC 29110 standard, including the rationale behind its development and the innovative design of implementation guides to assist very small companies in adopting the standards, as well outlining a pilot project scheme for usage in early trials of this standard.

Modeling of an SMA actuator based on the Liang and Rogers model

The purpose of this study is to develop a complete mathematical model of a thick shape memory alloys (SMA) actuator based on the Liang and Rogers model. Due to hysteresis and significant nonlinearities in the behavior of shape memory alloy actuators, the modeling of SMA actuators has been a great challenge in recent years, which limit the application of these actuators. In this paper, a new model is used to represent the major and minor hysteresis loops of SMA actuator based on the Liang and Rogers model. The modified Liang and Rogers model of SMA wire actuated by an electric current is derived and several experiments are used to validate the model and to identify the parameters. A key feature of the proposed model is to predict the martensite starting temperature of minor loops. This model can be used to develop a position control system for the SMA actuator. Simulation results for the model are found to be in good agreement with experimental data.

Using Rogers's Diffusion of Innovation Model to Examine the Willingness to Pay for Public Television in Taiwan

This study adopts Rogers's diffusion of innovation model to examine the factors affecting the willingness of the Taiwanese to pay a license fee to watch public television. A telephone survey was used, and 506 valid questionnaires were obtained, representing a response rate of 58.6%. The data analysis showed that most findings of this study were not congruent with the prediction of Rogers's model, indicating that the Taiwanese do not consider paying a license fee a feasible means to support public television. However, this study found that the frequency of public television viewing was the most powerful factor positively affecting people's intention to pay for public television.

Are e‐books replacing print books? tradition, serendipity, and opportunity in the adoption and use of e‐books for historical research and teaching

This article aims to understand the adoption of e‐books by academic historians for the purpose of teaching and research. This includes an investigation into their knowledge about and perceived characteristics of this evolving research tool. The study relied on Rogers's model of the innovation‐decision process to guide the development of an interview guide. Ten semistructured interviews were conducted with history faculty between October 2010 and December 2011. A grounded theory approach was employed to code and analyze the data. Findings about tradition, cost, teaching innovations, and the historical research process provide the background for designing learning opportunities for the professional development of historians and the academic librarians who work with them. While historians are open to experimenting with e‐books, they are also concerned about the loss of serendipity in digital environments, the lack of availability of key resources, and the need for technological transparency. The findings show that Rogers's knowledge and persuasion stages are cyclical in nature, with scholars moving back and forth between these two stages. Participants interviewed were already weighing the five characteristics of the persuasion stage without having much knowledge about e‐books. The study findings have implications for our understanding of the diffusion of innovations in academia: both print and digital collections are being used in parallel without one replacing the other.

Sources of variation in social networks

What explains the large variation in the number of contacts (degree) that different participants of social networks have: age, randomness, or some unobservable fitness measure? To answer this question, I extend the model presented in Jackson and Rogers (2007) to allow individuals to vary in their ability to attract contacts. I estimate the parameters of the extended model, using a social network of citations among high-energy physics papers, and find that the extended Jackson–Rogers model can parsimoniously fit the degree distribution of each age cohort. Moreover, both the length of time spent in the network and the unobservable fitness measure are important in explaining the observed variation in participantsʼ degrees.

Exponential Sum Modeling of Reswick and Rogers Pressure-Duration Curve: A New Analysis and Model

Reswick and Rogers model is not valid for predicting the effects of short- and long-time tissue exposures to contact pressures because it lacks intercepts. A different model, without those asymptotic properties, that could fit the shape of the curve well, could potentially provide useful information. We used modeling to test the hypotheses that an exponential model could fit Reswick and Rogers pressure-duration curve, and, if so, to determine the order of the best fit exponential model. Up to four exponential sum models were fit. Three exponentials provided the best fit [Weighted sum-of-squared residuals 72, Akaike Information Criterion 89, r=0.997]. Thereby identifying three homogeneously distinct anatomical pressure-load containing tissue compartments: skin, fat, and muscle. A fourth compartment, bone, could not be identified because of limited resolution of the data. Our results suggest that the fat pressure-load containing compartment may play an adaptive compensatory preventive role in response to pressure loads—“a cushion effect.” Exponential sum modeling of pressure-duration curves provides a new approach for studying the dynamics of compression in normal and disease states in humans, and it may be useful for practical application at the point-of-care to assist with prevention and treatment of pressure ulcers.

Awareness of Internet Plagiarism Among The Secondary School Students in Gombak, Selangor, Malaysia

Plagiarism has long been a problem in educational setting and with the advent of the Internet revolution and highly user-friendly word processing software, plagiarism has become a widespread phenomenon. Internet exposes students to a multitude of resources in their learning process. Ironically, these phenomena also brought tremendous opportunities for the plagiarism on cyberspace to take place. Students freely copy and paste informations directly from Internet in the assignments and claimed the works as theirs. Very limited research had been done and there are no study had been conducted in secondary school students in Malaysia. This study aims to investigate the reasons behind the increased phenomena of the internet plagiarism among students in one of the secondary schools in Gombak, Selangor, Malaysia. Data collection and the subsequent analyses were guided by qualitative research methods with the theoretical backdrop of Rogers Model of Innovation-Decision Process (Rogers, 1962). In this research, researcher uses the term “awareness of the internet plagiarism” as the “innovation”. 4 themes emerged from this research, namely (1) lack and limited knowledge (2)lack and limited awareness and (3) normal phenomena (4) easy access to Internet. These themes are discussed with reference to the finding of other studies in plagiarism and the implication for the continuum of the education in Malaysia is pointed out. Keywords - internet plagiarism, secondary school student, Gombak, Selangor, Malaysia

Robustness for path-dependent volatility models

In this paper, we consider a generalisation of the Hobson–Rogers model proposed by Foschi and Pascucci (Decis Eocon Finance 31(1):1–20, 2008) for financial markets where the evolution of the prices of the assets depends not only on the current value but also on past values. Using differentiability of stochastic processes with respect to the initial condition, we analyse the robustness of such a model with respect to the so-called offset function, which generally depends on the entire past of the risky asset and is thus not fully observable. In doing this, we extend previous results of Blaka Hallulli and Vargiolu (2007) to contingent claims, which are globally Lipschitz with respect to the price of the underlying asset, and we improve the dependence of the necessary observation window on the maturity of the contingent claim, which now becomes of linear type, while in Blaka Hallulli and Vargiolu (2007), it was quadratic. Finally, in this framework, we give a characterisation of the stationarity assumption used in Blaka Hallulli and Vargiolu (2007), and prove that this model is stationary if and only if it is reduced to the original Hobson–Rogers model. We conclude by calibrating the model to the prices of two indexes using two different volatility shapes.

Functional and Numerical Responses of Scymnus Syriacus Marseul (Coleoptera: Coccinellidae) to the Black Bean Aphid, Aphis Fabae Scopoli (Hemiptera: Aphididae) Under Laboratory Conditions

Functional and Numerical Responses ofScymnus SyriacusMarseul (Coleoptera: Coccinellidae) to the Black Bean Aphid,Aphis FabaeScopoli (Hemiptera: Aphididae) Under Laboratory ConditionsFunctional and numerical responses are basic to any investigation of predator-prey relationships and key components in the selection of predators for biological control. In this study, functional and numerical responses of the female and male ladybeetles,Scymnus syriacusMarseul to different densities of third instar nymphs ofAphis fabae(i.e.5, 10, 20, 30, 40, 60 and 80) as prey, were studied in a growth chamber (25°C, 65±5% RH and a photoperiod of 16L : 8D h) on the broad bean,Vicia fabaeLinn. Using the logistic regression, a type II functional response for both female and male ladybeetles was determined. Using Nonlinear least-square regression, the searching efficiency (a') and handling times (Th) of the female and male adults were estimated as 0.123±0.006 h, 0.434±0.012 h and 0.115±0.008 h, 0.514±0.016, respectively. The Rogers model was used to estimate the maximum theoretical predations (T/Th) for female and male, which were 55.18 and 46.64, respectively. These results indicated a higher efficiency in female ladybeetles. The reproductive numerical response, in terms of eggs laid, increased curvlinearly with increasing prey density. The reproductive response trend was similar to the shape of the type II functional response. This similarity means both responses are interlinked and function simultaneously. The efficiency of the ingested food conversion (ECI) of the females decreased with prey density, as females laid 25±0.65 eggs when exposed to the highest prey density (80) and 3±0.44 eggs at lowest prey density (5).

A NUMERICAL SIMULATION OF CARDIAC ELECTRIC ACTIVITY IN LV BASED ON MONO-DOMAIN MODEL

Heterogeneities of ionic current expression and electrophysiological characteristics exist within the mammalian ventricle wall and are assumed to be the result of regional differences in myocardial membrane ionic current densities. This work describes computational approaches of modeling the cardiac cellular excitability and electrical activity propagation in the spatially inhomogeneous ventricular tissue. A three-dimensional (3D) unsteady Rogers model with one gating variable has been considered for simulating the cardiac electrical activity. Based on the paradigm of domain decomposition a 3D finite element scheme has been developed and implemented using PETSc Library under MPI environment. The numerical simulations are carried out on IBM SP3 machine. The computational studies provide insight into the underlying mechanisms during the normal and pathological cardiac excitation.

A Study of the Feasibility of Introducing Therapeutic Touch Into the Operative Environment With Patients Undergoing Cerebral Angiography

The purpose of this pilot study was to determine whether Therapeutic Touch (TT) can be effectively used in the operative setting and whether it could produce positive outcomes in the period from cerebral angiography to discharge. The specific outcomes to be assessed were blood pressure, pulse, and respirations. TT is an intervention that involves the intentional direction of energy for the purpose of healing. The present study was developed within the conceptual framework of Rogers's model of unitary human beings. Data were collected at a center for endovascular surgery. The participants were 40 men and women aged between 18 and 80 years who were referred to the center for cerebral angiograms. The participants were English-speaking, ambulatory patients, with no history of prior cerebral angiograms and no psychiatric diagnosis. The design was a randomized, single-blind experiment. The research data were collected in the normal course of the angiogram procedure and recovery room. The blood pressure, pulse, and respirations were routinely noted before, during, and after the procedure. The study was significant in three aspects: (a) it was the first study to develop a protocol for delivering TT in the preoperative course of neurological patients, (b) the study is conceptualized within Rogers's conceptual model of unitary human beings, and (c) the study explored the impact of TT on selected outcomes in endovascular patients. A protocol for delivering TT in the operative setting was successfully developed and implemented. The efficacy of TT on the blood pressure, respirations, and pulse of the experimental group was not statistically significant. The reasons for this finding are explored, and suggestions are made for future research.

Thinking inside the box

A widespread turn towards mechanism-centred explanations can be viewed across the social sciences in recent decades. This article clarifies what it might mean in practical terms to adopt a mechanismic view of causation. This simple task of definition turns out to be considerably more difficult than it might at first appear. The body of the article elucidates a series of tensions and conflicts within this ambient concept, looking closely at how influential authors have employed this ubiquitous term. It is discovered that ‘mechanism’ has at least nine distinct meanings as the term is used within contemporary social science: (1) the pathway or process by which an effect is produced; (2) an unobservable causal factor; (3) an easy-to-observe causal factor; (4) a context-dependent (bounded) explanation; (5) a universal (or at least highly general) explanation; (6) an explanation that presumes highly contingent phenomena; (7) an explanation built on phenomena that exhibit lawlike regularities; (8) a distinct technique of analysis (based on qualitative, case study, or process-tracing evidence); or (9) a micro-level explanation for a causal phenomenon. Some of these meanings may be combined into coherent definitions; others are obviously contradictory. It is argued, however, that only the first meaning is consistent with all contemporary usages and with contemporary practices within the social sciences; this is therefore proposed as a minimal (core) definition of the concept. The other meanings are regarded as arguments surrounding the core concept.

In this issue

In this issue

Effectiveness of a videoconference training course on implementing pharmacy services

The aim of this research was to assess the effects of a series of four training courses comprised of 13 synchronous videoconferences on the implementation of cognitive services in Spanish community pharmacies. Setting A phone survey to continuing training course attendants. A random sample of 225 pharmacists registered in a 2004 videoconference course was selected. The phone-survey questionnaire included quality perception elements rated on a 5-point Likert scale, and a series of questions used to identify position in the Rogers 5-step innovation-decision model. An algorithm was used to translate the questions into Rogers' categories. To discover determinants of attendants position in these categories, bivariate analysis, simple correspondence analysis, and logistic regressions were performed. Position in Rogers' diffusion of innovation steps regarding the adoption of pharmacotherapy follow-up. The perception of the course quality rated between good and very good for the majority of respondents. A significant association between having attended two or more of these four courses and the Persuasion/Decision step in Rogers's model appeared. No association was found between course attendance and the Implementation/Confirmation step of patient follow-up. Fifty percent of those who indicated they implemented the service reported following-up with less than 10 patients, and only 25% reported following up with more than 20 patients. Although participation in these courses was associated with higher steps in Rogers' model, significant association appeared only with Persuasion/Decision steps and not with the Implementation/Confirmation step, reflecting an attitude but not a performance change.

A Demographic Model for Small Area Population Projections: An Application to the Census Metropolitan Area of Hamilton in Ontario, Canada

This paper reports on the development of a demographic model capable of projecting the spatial distribution of population by age and sex for small areas such as census tracts. The proposed modeling framework makes use of two components: the Rogers multiregional population projection model and the aggregate spatial multinomial logit (ASMNL) model. The Rogers model utilizes cohort vital statistics on fertility, mortality, and migration to project the progression of population by age and sex at the regional level, while the ASMNL model extends the capabilities of the Rogers model enabling it to provide population estimates at a finer spatial scale. The model is applied to the Hamilton Census Metropolitan Area in Canada. Our simulation tests highlight the robustness of the proposed modeling approach in utilizing small area characteristics and regional vital statistics to perform small area population projections.

Temperature-dependent functional response of Scolothrips longicornis (Thysanoptera: Thripidae) preying on Tetranychus urticae

Environmental variables like temperature are important factors that affect the efficiency of biological control agents in greenhouse crops. This study examined the effect of temperature on the functional response of an acarophagous thrips Scolothrips longicornis Priesner to different densities of two spotted spider mite, Tetranychus urticae Koch in laboratory conditions. Five constant temperatures (15, 20, 26, 30, and 35 °C) and seven prey densities (2, 4, 8, 16, 32, 64, and 128) were used in the experiments. At each temperature, 2 to 128 adult of T. urticaue were exposed to a female S. longicornis for a 24 h period. The results indicated that the predatory thrips exhibited type II functional response to different densities of T. urticae at all examined temperatures. Temperature had significant effect on the predation capacity of the adult thrips over the range of 15–35 °C. Instantaneous attack rate ( a) of the predator increased linearly with increasing temperature from 15 to 35 °C. At 35 °C, the highest instantaneous attack rate was estimated to be 0.0579 day − 1 using the Holling model and 0.1480 day − 1 using Rogers model. The estimated value of handling time ( T h) using both Holling and Rogers models decreased linearly with increasing temperature from 15 to 35 °C. Scolothrips longicornis achieved higher predation at higher temperature (16.1 preys/day at 35 °C). This observation suggested that S. longicornis may be more effective for biological control of two spotted spider mite in warmer conditions.

RATE OF CONVERGENCE OF MONTE CARLO SIMULATIONS FOR THE HOBSON–ROGERS MODEL

The Hobson–Rogers model is used to price derivative securities under the no-arbitrage condition in a stochastic volatility setting, preserving the completeness of the market. Here we are studying the rate of convergence of the Euler/Monte Carlo approximations, when pricing European, Asian and digital type options. The aim of the present work is to express the approximation error in terms of the time step size, denoted by h, used for the Euler scheme. We recover an already known result, obtained by other authors using PDE approximations, for European options. Namely we show that for a Lipschitz coefficient of the driving equations for the asset price and Lipschitz payoffs, we obtain an error of the order of [Formula: see text]. Moreover, using Malliavin Calculus techniques, we show that with a regular coefficient we may attain an error of the order of h for regular payoffs and of the order of [Formula: see text] for non Lipschitz payoffs. Finally we show some numerical simulations supporting our theoretical results.

Calibration of a path-dependent volatility model: Empirical tests

The Hobson and Rogers model for option pricing is considered. This stochastic volatility model preserves the completeness of the market and can potentially reproduce the observed smile and term structure patterns of implied volatility. A calibration procedure based on ad-hoc numerical schemes for hypoelliptic PDEs is proposed and used to quantitatively investigate the pricing performance of the model. Numerical results based on S&P500 option prices are discussed.

Permeation selectivity of gaseous isotopes through dense polymers: Peculiar behavior of the hydrogen isotopes

The small but significant difference in permeation rates of gaseous isotopes through dense polymers has been previously reported in several studies. Most results remain, however, restricted to hydrogen isotopes. In this study, the steady-state permeation selectivity of a series of seven different gaseous isotopes pairs (D/H, 13C/ 12C, 15N/ 14N, 18O/ 16O, 17O/ 16O, and 36Ar/ 40Ar), covering a broad range of molecular weights (H 2, N 2, Ar, O 2, and CO 2), has been investigated through two dense polymeric structures (PDMS and PTFE). It is shown that, with the notable exception of the H 2/HD pair, isotope permeation selectivity can be described for each polymer type through a single expression as a function of the relative molecular weight difference. We show, for the first time, that this behavior is consistent with Frisch and Rogers (1964) model. More interestingly, it suggests that the peculiarities of the H 2/D 2 pair, such as the high-relative mass difference or small size, may explain the inadequacy of the gas in a box quantum approach for this case.

Adoption and Implementation of Mandated Diabetes Registries by Community Health Centers

Innovations adopted by healthcare organizations are often externally mandated. However, few studies examine how mandated innovations progress from adoption to sustained effective use. This study uses Rogers's model of organizational innovation to explore community health centers' (CHCs') mandated adoption and implementation of disease registries in the federal Health Disparities Collaborative (HDC). Case studies were conducted on six CHCs in North Carolina participating in the HDC on type 2 diabetes mellitus. Data were collected from semistructured interviews with key staff, and from site-level and individual-level surveys. Although disease registry adoption and implementation were mandated, CHCs exercised prerogative in the timing of registry adoption and the functions emphasized. Executive and medical director involvement, often directly on the HDC teams, was the single most salient influence on adoption and implementation. Staff members' personal experience with diabetes also provided context and gave registries added significance. Participants lauded HDC's technique of small-scale, rapid-cycle change, but valued even more shared problem solving and peer learning among HDC teams. However, lack of cross-training, inadequate resources, and staff turnover posed serious threats to sustainability of the registries. The present study illustrates the usefulness of Rogers's model for studying mandated innovation and highlights several key factors, including direct, personal involvement of organizational leadership, and shared problem solving and peer learning facilitated by the HDC. However, these six CHCs elected to participate early in the HDC, and may not be typical of North Carolina's remaining CHCs. Furthermore, most face important long-term challenges that threaten routinization.