Graphical Trends Research Articles

Conductivity models for Archie rocks

The petroleum industry’s standard porosity-resistivity model (i.e., Archie’s law), although it is fit for its purpose, remains poorly understood after seven decades of use. This results from the choice of the graphical display and trend formula used to analyze Archie’s seminal porosity-resistivity data, taken in the Nacatoch sandstone, a petroliferous clastic formation in the Gulf of Mexico coastal area. Archie’s model accurately predicts the conductivity-brine volume trend for this sandstone. Not all rocks follow the same porosity-resistivity trends observed in the Nacatoch sandstone, but those that do are defined as Archie rocks. Archie’s Nacatoch sandstone data set has significant irreducible scatter, or noise. Data with significant scatter cannot be used to uniquely define a trend. Alternative graphical analyses of Archie’s Nacatoch sandstone data indicates that Archie could have analyzed these data differently had it occurred to him to do so. A physics-based porosity-conductivity model, a “geometrical factor theory” (GFT), is preferred as an alternative to the Archie model because it has a physical interpretation. In this model, the bulk conductivity of an Archie rock is the product of three factors: brine conductivity, fractional brine volume, and an explicit geometrical factor. The model is offered in the form of a theorem, proved in three steps, to make our arguments as explicit and transparent as possible. The model is developed through its culmination as a saturation equation to illustrate that it is a complete theory for Archie rocks. The predictive power of the Archie model and GFT are similar, but unlike the adjustable parameters of the Archie model ([Formula: see text], [Formula: see text], and [Formula: see text]), all of the parameters of GFT have a priori physical interpretations. Through a connection to site percolation theory, GFT has promise to connect porosity-conductivity interpretation to circuit theory first principles.

The Effect of a Graphical Interpretation of a Statistic Trend Indicator (Trigg's Tracking Variable) on the Detection of Simulated Changes

Anaesthesia involves processing large amounts of information over time. One task of the anaesthetist is to detect substantive changes in physiological variables promptly and reliably. It has been previously demonstrated that a graphical trend display of historical data leads to more rapid detection of such changes. We examined the effect of a graphical indication of the magnitude of Trigg's Tracking Variable, a simple statistically based trend detection algorithm, on the accuracy and latency of the detection of changes in a micro-simulation. Ten anaesthetists each viewed 20 simulations with four variables displayed as the current value with a simple graphical trend display. Values for these variables were generated by a computer model, and updated every second; after a period of stability a change occurred to a new random value at least 10 units from baseline. In 50% of the simulations an indication of the rate of change was given by a five level graphical representation of the value of Trigg's Tracking Variable. Participants were asked to indicate when they thought a change was occurring. Changes were detected 10.9% faster with the trend indicator present (mean 13.1 [SD 3.1] cycles vs 14.6 [SD 3.4] cycles, 95% confidence interval 0.4 to 2.5 cycles, P = 0.013. There was no difference in accuracy of detection (median with trend detection 97% [interquartile range 95 to 100%], without trend detection 100% [98 to 100%]), P = 0.8. We conclude that simple statistical trend detection may speed detection of changes during routine anaesthesia, even when a graphical trend display is present.

Study of Salinity and pH Effects on Gelation Time of a Polymer Gel Using Central Composite Design Method

Experiments were conducted to investigate the main effects of salinity (NaCl) concentrations and pH factors and their interactions on the gelation time response of a polymer gel used in a water shutoff system in oil field reservoirs. Central composite design (CCD) was used to design experiments and a mathematical model building. The main advantage of CCD was to generate the quadratic mathematical model for the gelation time as functions of salinity and pH factors. Tests were limited and optimized by CCD points including low star (axial), low factorial, central, high factorial, and high star points. The evaluation of the data and the developed model were performed through the examination of graphical trend of residuals and a numerical approach. Analysis of variance (ANOVA) was used to estimate the amount of data variations from the model predictions. It was found that the model was significant at the 99% confidence against test data. The results showed that the gelation time was dependent more on pH than salinity. For low pH, the gelation time increased with increasing of the salinity, while for a high pH (>4) the relationship was inversed. The research shows that CCD can effectively be applied for the modeling of gelation time and finding an optimum condition to achieve maximum or minimum gelation time for different salinity and pH factors.

Mathematical Counterstory and African American Male Students: Urban Mathematics Education From a Critical Race Theory Perspective

In this article, the author argues that the persistent underachievement of many African American male students in urban school districts requires pedagogical interventions designed to re-engage and re-orient students to mathematics as a critical cultural activity. While counterstory, a critical race theory construct, has wide application across educational research, few researchers have explored its relevance for urban mathematics education. Here, the author provides a grounded operationalization of counterstory by examining the pedagogy embedded in African American narrative on literacy. Using data from a participatory action research project involving male African Americans in South Los Angeles, the author then demonstrates how counterstory is embedded in the mathematical activity associated with graphical representation and trend analysis of data. Through the theorized approach to counterstory presented, the author provides useful direction for education researchers interested in counterstory, and for mathematics educators attempting to broaden their pedagogical approaches to teaching and learning mathematics.

Learning curves of novice anesthesiology residents performing simulated fibreoptic upper airway endoscopy

In various medical and surgical specialties, it is essential to acquire fibreoptic upper airway endoscopy skills for successful endotracheal intubation, especially when faced with a difficult airway. The aim of our study was to evaluate the learning curves of residents performing fibreoptic upper airway endoscopy in the simulation environment. Following a standardized video and practice session, 16 residents newly enrolled in the anesthesiology program performed nasal fibreoptic endoscopy of the upper airway (endpoint being the carina) on a high fidelity simulator. Weekly 20-min sessions continued for a period of one month. Each attempt was designated as either a "success" or a "failure" based on the study participant's ability or inability to visualize the carina in ≤60 sec and with ≤five collisions with the simulated mucosal wall. Proficiency was attained when the downward graphical trend of the cumulative sum (CUSUM) analysis crossed two adjacent boundary lines, i.e., an acceptable failure rate was reached. The residents' mean number of attempts at fibreoptic airway endoscopy was 47 (9) with a range of 32-64. Time to visualization of the carina was 51 (36) sec. Three classical patterns of CUSUM trends were observed: proficient (n=7); not proficient with a downward (improvement) trend (n=3); and not proficient with an upward (worsening) trend (n=6). The number of attempts at which proficiency was achieved varied from 27 to 58. There is a large variation in the learning curves of residents performing fibreoptic upper airway endoscopy. The training for fibreoptic airway endoscopy should be tailored to the needs of each individual.

Overall equipment effectiveness (OEE) and process capability (PC) measures

Purpose – Overall equipment effectiveness (OEE) and process capability (PC) are commonly used and well‐accepted measures of performance in industry. These measures, however, are traditionally applied separately and with different purposes. The purpose of this paper is to investigate the relationship between OEE and PC, how they interact and impact each other, and the possible effect that this relationship may have on decision making.Design/methodology/approach – The paper reviews the OEE and PC background. Then, a discrete‐event simulation model of a bottling line is developed. Using the model, a set of experiments are run and the results interpreted using graphical trend and impact analyses.Findings – The paper demonstrates the relationship between OEE and PC and suggests the existence of a “cut‐off point” beyond which improvements in PC have little impact on OEE.Practical implications – PC uses the capability indices (CI) to help in determining the suitability of a process to meet the required quality s...

The influence of various graphical and numeric trend display formats on the detection of simulated changes*

Integration of a large amount of information is important in anaesthesia but there is little research to guide the development of data displays. Anaesthetists from two hospitals participated in five related screen based simulation studies comparing various formats for display of historical or 'trend' data. Participants were asked to indicate when they first noticed a change in each displayed variable. Accuracy and latency (i.e. delay) in detection of changes were recorded. Latency was shorter with a graphic display of historical data than with a numeric display. Increasing number of variables or reduction of y-axis height increased the latency of detection. If the same number of data points were included, there was no difference between graphical and numerical displays of historical data. There was no difference in accuracy between graphical or numerical displays. These results suggest that the way trend data is presented can influence the speed of detection of changes.

Health Selection vs. Causation in the Income Gradient: What Can We Learn from Graphical Trends?

Income produces health, and sickness negatively affects earnings. These two factors likely explain the income gradient in health, but each has very different policy implications. In this paper, I examine graphical trends in mortality risk between low-income and higher-income people by age and gender. These trends suggest that forward causality (income affecting health) is more important than reverse causality (health affecting income) in the income-health gradient. However, there is some evidence to suggest that reverse causality plays an important role for younger men.

Changes in T-wave amplitude in patients with peripheral edema: implications for patients with congestive heart failure and assessment of the T-wave alternans

developed biopotential fiber sensors (BFSs) will reduce the noise artifacts and thus result in a better ST-segment measurement sensitivity. Methods: We recorded 12-lead ECGs simultaneously from wet gel electrodes and from low-mass, nonmetallic BFS assemblies in routine stress testing of the obese patients. The stress test ECG signals were recorded using the X-Scribe II system and a hi-resolution H-12 Holter, both from Mortara Instruments. In each ECG comprising preexercise, peakexercise, and postexercise phases, we have computed mean sinus rhythm cycles then synchronized them with the raw signal and subtracted. The resulting “residue” (noise) was quantified by computing its SD and rootmean-square of successive differences in each signal. We then computed ST levels and J-ST delays in both ECGs for individual beats and on all 12 mean complexes. We evaluated the results using graphic trends of the computer-generated ST measurements and histograms of the differences between the BFS data–generated ST values and the Ag-AgCl electrode data ST values. Two performance measures, the ST measurement sensitivity and the ST measurement positive predictivity, were used to quantify the performance results of the comparison study. This technique allows for accurate evaluation and quantification of the impact of noise on the performance of the ST measurements in both data sets. Results and conclusions: The root-mean-square of successive differences residuum values were significantly lower with the BFS sensors (16.62 ± 2.71 μV) than with the Ag-AgCl electrodes connected to patient cables (37.47 ± 11.69 μV, P b .001 and P b .002). The ST measurement sensitivity and ST measurement positive predictivity were significantly higher for the BFS signals: 75% vs 52% and 64% vs 46, respectively, for Ag-AgCl electrode signals. We conclude that ECGs from BFS were less noisy than from AgAgCl electrodes, resulting in higher ST-segment measurement sensitivity.

On the Verge of Ptolemaic Egyptian: Graphical Trends in the 30th Dynasty

On the Verge of Ptolemaic Egyptian: Graphical Trends in the 30th Dynasty

Gender and Commercial Science: Women’s Patenting in the Life Sciences

Traditional research on gender differences in productivity focuses on academic scientists, and rarely investigates outcomes other than publications. We investigate gender disparities in commercial outcomes, for scientists in both the academic and industrial sectors. Using a unique combination of career history data and patenting information across a period of two decades, we present descriptive statistics and graphical trends of male and female commercialization. Empirical evidence indicates that female scientists engage in and produce less commercial work then their male counterparts, and that the degree of disparity remains constant across time. The quality and impact of women’s commercial work remains the same or better than that of men scientists, however. These results imply that a necessary focus for future work is to understand the personal, structural, and organizational reasons for the filtering process which leads to such a small proportion of female inventors.

Career-Span Analyses of Track Performance: Longitudinal Data Present a More Optimistic View of Age-Related Performance Decline

Sport scientists (Starkes, Weir, Singh, Hodges, & Kerr, 1999; Starkes, Weir, & Young, 2003) have suggested that prolonged training is critical for the maintenance of athletic performance even in the face of predicted age-related decline. This study used polynomial regression analyses to examine the relationship between age and running performance in the 1500 and 10,000 metre events. We compared the age and career-longitudinal performances for 15 male Canadian Masters athletes with a cross-sectional sample of performances at different ages. We hypothesized that the 30 years of uninterrupted training characteristic of this longitudinal sample would moderate the patterns of age-related decline (retention hypothesis); alternatively, the cross-sectional data were expected to demonstrate pronounced age-related decline (quadratic hypothesis). Investigators performed multimodel regression analyses on the age and performance data. Based on the absence (for longitudinal data) or presence (for the cross-sectional data) of significant quadratic components in second-order polynomial models, the authors found support for their respective hypotheses. The longitudinal data showed that running performance declined with age in a more linear fashion than did cross-sectional data. Graphical trends showed that the moderation of age-related decline appeared greater for the longitudinal 10 km performances than for the 1500 m event.

Future trends in computer graphics: How much is enough?

Over the forty-year history of interactive computer graphics, there have been continuous advances, but at some stage this progression must terminate with images being sufficiently realistic for all practical purposes. How much detail do we really need? Polygon counts over a few million imply that on average each polygon paints less than a single pixel, making use of polygon shading hardware wasteful. We consider the problem of determining how much realism is required for a variety of applications. We discuss how current trends in computer graphics hardware, and in particular of graphics cards targeted at the computer games industry, will help or hinder achievement of these requirements. With images now being so convincingly realistic in many cases, critical faculties are often suspended and the images are accepted as correct and truthful although they may well be incorrect and sometimes misleading or untruthful. Display resolution has remained largely constant in spatial terms for the last twenty years and in terms of the number of pixels has increased by less than an order of magnitude. If the long-promised breakthroughs in display technology are finally realised, how should we use the increased resolution?

Symptom based diagnostic system for nuclear power plant operations using artificial neural networks

Abstract Nuclear power plant experiences a number of transients during its operations. These transients may be due to equipment failure, malfunctioning of process systems and unavailability of safety systems. In such a situation, the plant may result into an abnormal state which is undesired. In case of an undesired plant condition generally known as an initiating event (IE), the operator has to carry out diagnostic and corrective actions. The operator's response may be too late to mitigate or minimize the negative consequences in such scenarios. The objective of this work is to develop an operator support system based on artificial neural networks that will assist the operator to identify the IEs at the earliest stages of their developments. These abnormal plant conditions must be diagnosed and identified through the process instrument readings. A symptom based diagnostic system has been developed to investigate the IEs. The event identification is carried out by using resilient back propagation neural network algorithm. Whenever an event is detected, the system will display the necessary operator actions in addition to the type of IE. The system will also show the graphical trend of relevant parameters. The developed system is able to identify the eight IEs of Narora Atomic Power Station. This paper describes the features of the diagnostic system taking one of the IEs as a case study.

Inside design now: National Design Triennial

Inside Design Now takes the pulse of American design in the new millennium, providing a fascinating tour of cutting-edge trends in architecture, interiors, landscape, fashion, graphics, and new media. Featuring eighty emerging and established designers including 2 x 4, Mike Mills, Peter Eisenman, Fuse Project, Tod Machover, Paula Scher, Jennifer Siegal, and Isaac Mizrahi Inside Design Now illustrates the most innovative and provocative thinking in design today. Each designers work is presented with a double-page spread and a series of full-color images. Essays explore the role of the designer in todays culture, contemporary ideas of beauty and functionality, and what the future holds in the realm of design. Sensuous materials, lush patterns, and exquisite details come together with new technologies, pop imagery, and fresh approaches to scale, color, and construction in the works reproduced in this volume. Inside Design Now accompanies the exhibition of the same name at the Cooper Hewitt Museum of National Design beginning in April 2003.

Groundwater quality monitoring

The paper describes results of monitoring activities of groundwater in a rural area carried out to verify the impact on water quality in an uncontaminated area resulting from the initiation of an atmospheric pollution source. Significant emissions of nitrogen oxides from the pollution source resulted in particular attention to verifying the increase of nitrate concentrations in monitored water. Over 10,000 analytical tests including several chemical parameters were conducted in the full monitoring period. In the paper, a first reading of data, graphical trends and non-parametric statistical analysis are presented. Measured values for nitrates, nitrites, hardness, alkalinity and pH showed poor variability during the entire period. Checked parameters were in the usual ranges of uncontaminated rural areas and comparisons between meaningful values of the periods ante operam and post operam do not show any degradation of water quality following the atmospheric pollution source activity. Nitrites are occasionally found in some spring water due to organic pollution, confirmed by the randomness with which their presence was detected.

Dynamic evaluation approach for virtual conflict decision training

Conflict decision is a continuous decision process in a dynamic conflict environment. The evaluation of the dynamic conflict situation is the basis of making proper decisions at different stages of the conflict process. Traditional evaluation approaches are static and do not consider enough impact factors in real conflict environment, so cannot reflect the real conflict situation and its evolution. This paper presents a dynamic evaluation framework for supporting continuous decisions in dynamic conflict environments. The framework includes the timed evaluation models for conflict force, conflict situation, and psychological pressure, as well as a graphical trend analysis approach. The framework has been applied to a virtual military conflict decision training system. A set of dynamic curves is used to intuitively reflect the dynamic evaluation result. Decision makers can know the current conflict situation and its evolution process through these dynamic curves at any stage of the conflict process so can make more evidential decisions.

Informing patients: a guide for providing patient health information.

To understand and address patients' need for information surrounding ambulatory-care visits. The authors conducted two patient focus groups regarding patient education. The first covered general information needs of patients and the second explored their reactions to a computer-generated patient handout that was developed in response to the results of the first focus group and implemented in a clinic. Participants sought information about their health--generally after the encounter with their caregiver. They wanted a permanent record of personal health data and relevant educational information. Participants recommended that the information be concise, clear, and illustrated with graphics if appropriate. Receiving health-related information from their providers favorably affected the participants' trust in, relationship with, and confidence in their physicians. When given printouts with graphic trends depicting their responses to therapy, participants reported that they were more motivated to adhere to a treatment plan and were more satisfied with their care. Based on the results of the focus groups, we developed a set of attributes (P.A.T.I.E.N.T.) to guide the development of patient and consumer health information. Patients participating in our focus groups felt that providing printed summary information to patients at the end of a clinic visit improves their understanding of their care, enhances their relationships with providers, improves their satisfaction with care, and motivates them to adhere to treatment plans. Further empirical studies are necessary to test their perceptions.

Core software for on-line data acquisition and post-hoc analysis: report of clinical testing and evaluation

The continuing progress of standard medical care results in an overload of patient's data, which are difficult to handle by traditional techniques. A software package is perspectively an appealing choice to deal with such a challenge. Aim of this study was the development and testing of an automated real-time data acquisition and analysis system for intensive care survey. The system included two PCs, the first for data acquisition (PC1: 166 MHz Pentium CPU, 32 MB RAM, 2 GB HDD, A/DC National Instruments AT-MIO 16E-10), and the second for data analysis (PC2: 200 MHz Pentium CPU, 32 MB RAM, 2 GB HDD). PCs were both networked, with shared HDDs, keyboard, mouse, video output, and printout subsystem. Complete hemodynamic, respiratory and neurological parameters were monitored by HP Component Monitoring System 66S/68S, which included a VueLink interface to coupled ventilators and Licox GMS, Serial Output (RS-232, 38400 baud per s) and up to 8 waveform analog outputs. Original software for data acquisition, storage and analysis was developed by object-oriented LabVIEW 4.0. Data acquisition was performed by PC1. At start, the user is allowed to select up to 51 numerical parameters (serial input RS 232, 4 data strings per min) and up to 16 waveforms (analog input, sampling rate: 128–256–512 points per s). Flag points (free-text or codified) could be added. As an example, it was possible to display the waveforms, up to 5 trend graphs or 6 histograms of selected digital parameters. Up to 3 graphic trends from selected digital parameters were automatically printed on demand (every 6–8–12–24 h). The complete sets of numerical parameters were stored as following: a) read-only spreadsheet files, whose length was limited to 2 h each one because of technical reasons; b) daily spreadsheet files (1st data string of minute); c) binary files (waveform storage) with circular buffering in 48 h cycles (max. length). Post-hoc analysis was performed by PC2, regardless of eventual simultaneous data acquisition by PC1. When system starts, the user chooses the optional on-line or off-line work (from already stored data). The task can involve up to 8 digital parameters (trends) and up to 4 waveforms. Different software tools like cursors and pointers were available to retrieve significant events, to select time intervals and to zoom the graphs, allowing to perform different procedures. Analysis capabilities on numerical parameters (trends) included: frequency tables of selected parameters, numerical regressions, vector calculus. Input data from daily spreadsheet files could be edited. Waveform analysis included basic statistics, integral and derivative calculus. Different reports, graphs and tables were printed at request. The assessment of our system included a preliminary laboratory test and clinical tests. The system proved an easy interface to different equipment. The user interface and response times were favorably accepted. Data storage and display were reliable and flexible. The equipment can be located at patient bedside as conveniently as at a ward desk. The use of 2 CPUs linked in a local network allowed effective simultaneous data acquirement and analysis. Other features included highly configurable data acquisition, to suit the case at hand, easy and fast retrieval of information, automatic generation of complete and accurate reports to illustrate trends or to correlate different parameters. More extensive field tests should be carried out to assess the impact of the system to ICU and operating rooms and its effectiveness.

155 A RANDOMISED TRIAL OF COMPUTERISED TREND MONITORING

Hypothesis: Neonatal computerised trend monitoring (CTM) reduces the morbidity and mortality of infants receiving intensive care.Study type/Setting: Prospective cohort study in a tertiary neonatal service.Patients/Interventions: 445 conseculive newborn who required neonatal intensive care were randomised to receive CTM in addition to the use of conventional monitors (CM) or just CM. The CTM provides a graphical trend over time periods varying from 6 mins to 3 days for any combination (to a maximum of 5) of the monitored physiological or environmental parameters.Measurements: The following short term measures were compared daily over the first 7 days of life - periventricular haemorrhage (with grade - G (out of 4), flares - F (+/-), cysts - C (+/-) and ventricular size - VS (mms); doppler of the anterior cerebral artery - Rl; volume of colloid support - Vol (mls), and number of blood gases performed - BG (n). The outcome measures were death - D, abnormal ultrasound - US, percent discharged home D/C, time to death/discharge - tD/C (d), time ventilated - tV (d) and time in oxygen - tO2(d).Means/medians given as appropriate. Chi2 for categorised outcomes, Wilcoxon for quantitative outcomes and unpaired t test tor short term measures - all NSConclusions: CTM introduced into the management of intensive care neonates could not be demonstrated to improve short term outcome.