Hand-held Programmable Calculator Research Articles

Risk and Reward: Big Data and the Next Big Thing

President's column SPE presidents are asked a lot of questions, and I suppose that’s true of anyone who stands in front of an audience as an authority figure. I have learned to expect many of the same questions, no matter the audience: What will the price of oil do? When will the industry turn around? How is the industry managing post-Big Crew Change? What are you going to do to “fix” the situation of women in the industry? What is your view on climate change? But my favorite question is: What’s the Next Big Thing? As I travel around as SPE President, I see a lot of new and different technologies, operators, and ideas. But my view on the Next Big Thing has been consistent for the last few years: I believe that we are not only entering the era of universal big data, but also the era of more intelligent software to help us make better decisions. The software will help us be better engineers by preserving knowledge and improving decision making. I believe the Next Big Thing will be infinite big data and intelligent machines to interpret it. Cheaper and more robust sensors will allow us to collect data not only on expensive deepwater completions and big compressors, but also on every isolated onshore well. Cheaper computing power, universal communications, and learning algorithms will allow engineers to use and interpret those large amounts of data to manage assets more efficiently. I believe operators and service providers will be able to reduce risk by using the full value of knowledge and experience to optimize asset management. I learned to be an engineer in the analog world of the late 1970s and early 1980s. Ours was a world of hand-drawn maps and handwritten columns of figures on green engineering paper. Programmable handheld calculators replaced the slide rule. Data capture was infrequent, monthly at best, and analysis was slow and tedious. Enter the PC. I vividly remember first getting a PC at work in 1985 after I made the pitch to our district engineer to purchase an IBM PC Model XT for our six-person team. Before then, only special programs could be run on the mainframe at the faraway research center. Our group managed several Permian Basin waterfloods, and we had been doing very tedious calculations by hand. When I was pitching to the district engineer, his first question to me was “how many engineers will this PC replace?” What he didn’t see was that computational power would help the same number of engineers create better analysis and help drive better decisions. Since those ancient days of more than 30 years ago, better, faster, cheaper computing power is everywhere. We haven’t replaced engineers with PCs, but we have created new opportunities for better technical and economic evaluations. Enter the Internet. When I left ARCO in June 1994, engineers did not have email or Internet access. Three years later, I was emailing work across the Atlantic every day so that teams in Houston and London could collaborate. Now, especially for those of us in global companies, our workflows are completely dependent on instant global communications. But I believe we are only beginning to take advantage of the full potential of the globally connected computing world. The Internet, or Cloud, of Things is coming for all of us. Another question I’m often asked when I speak is: How will we manage the Big Crew Change? What will the industry do when all these people retire? How are we retaining the knowledge of all those experienced practitioners? I believe that many of my peers who are retiring or have retired as part of the Big Crew Change will continue to consult or work part-time on their own terms. But I think the greatest value will be for these experienced practitioners to help teach not just the next generation of human staff, but also the next generation of intelligent software. Their knowledge can be preserved forever in software that has learned how to duplicate, and eventually improve, their decisions.

Electronic Emissions Security: Danger in the Air

ABSTRACT Most organizations have measures to protect their network infrastructure from intruders. With the growth AND AVAILABILITY of wireless, some intruders now are aiming their attacks there. The potential for damage from these types of attacks is significant due to their nature. However, there is another type of wireless attack on organizational resources that also poses a significant vulnerability. That is electromagnetic radiation, also called radio frequency emissions (RFE), from unprotected systems and networks. Editor's note: When we received the HP model 45 handheld programmable calculators in the early 1970s, we could pickup the unit's clock with an FM radio. Presently, portable phone and wireless router/adapters often use the same 2.4 GHz frequency and don't co-exist well.

A multivariate logistic regression equation to screen for dysglycaemia: development and validation

To develop and validate an empirical equation to screen for dysglycaemia [impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and undiagnosed diabetes]. A predictive equation was developed using multiple logistic regression analysis and data collected from 1032 Egyptian subjects with no history of diabetes. The equation incorporated age, sex, body mass index (BMI), post-prandial time (self-reported number of hours since last food or drink other than water), systolic blood pressure, high-density lipoprotein (HDL) cholesterol and random capillary plasma glucose as independent covariates for prediction of dysglycaemia based on fasting plasma glucose (FPG)>or=6.1 mmol/l and/or plasma glucose 2 h after a 75-g oral glucose load (2-h PG)>or=7.8 mmol/l. The equation was validated using a cross-validation procedure. Its performance was also compared with static plasma glucose cut-points for dysglycaemia screening. The predictive equation was calculated with the following logistic regression parameters: P=1+1/(1+e-X)=where X=-8.3390+0.0214 (age in years)+0.6764 (if female)+0.0335 (BMI in kg/m2)+0.0934 (post-prandial time in hours)+0.0141 (systolic blood pressure in mmHg)-0.0110 (HDL in mmol/l)+0.0243 (random capillary plasma glucose in mmol/l). The cut-point for the prediction of dysglycaemia was defined as a probability>or=0.38. The equation's sensitivity was 55%, specificity 90% and positive predictive value (PPV) 65%. When applied to a new sample, the equation's sensitivity was 53%, specificity 89% and PPV 63%. This multivariate logistic equation improves on currently recommended methods of screening for dysglycaemia and can be easily implemented in a clinical setting using readily available clinical and non-fasting laboratory data and an inexpensive hand-held programmable calculator.

A Portable System for Reading Large Passive Integrated Transponder Tags from Wild Trout

Abstract This paper describes a system based on a commercial portable energizer–reader module and antennas and a hand-held programmable calculator for reading large (4 × 23 mm and 4 × 32 mm) passive integrated transponder (PIT) tags. Maximum tag-reading distances in water were 45 cm for ferrite-core stick antennas and 86 cm for a loop (gate) antenna; these distances varied with the size of the tags and their orientation to the antennas. The tags, tested on wild brown trout Salmo trutta and wild rainbow trout Oncorhynchus mykiss, were either inserted into the peritoneal cavity with a hypodermic needle or attached externally at the base of the dorsal fin with a fish hook and monofilament line. The fish were held in artificial channels 1 m wide and 50 m long and in two 3–4 m-wide stream sections, one 70 m long and the other 90 m long. During a 5-week period we were routinely able to detect marked fish by (1) walking along the channels and stream sections probing the water with an antenna, and (2) by position...

A GRAPHICAL OPTIMIZATION OF TAKE-OFF NOISE ABATEMENT PROCEDURES FOR SUBSONIC AIRCRAFT

This paper describes a numerical approach to the simulation of noise contours generated during aircraft operations. Common features of many existing noise-contour programs make these procedures unsuitable for on-line piloted-simulator use. In fact, they usually require large computational tools and exhibit complex structure, so that they generally run quite slowly. The method proposed here is an attempt to overcome some of the above drawbacks. It works for arbitrarily complex take-off and landing paths, and reveals the influence of several quantitites on the shape and size of the contours. Besides, the calculations are simple enough to be implemented on a handheld programmable calculator. The method runs fast, and quickly provides contour shape, evaluates area and analyzes main characteristics of the end. The method has been used to optimize noise abatement procedures for subsonic aircraft; for every take-off procedure the model can generate an isofootprint on the ground which helps the operator to choose the best take-off solution.

Jobsite Azimuths Made Easy with Mica

Finding the direction of a line is done simply and accurately with a multiyear interactive computerized almanac (Mica), a theodolite, and a hand-held programmable calculator. Mica is the Multiyear Interactive Computer Almanac that is available from the U.S. Naval Observatory. An astronomic azimuth from station 081 to station 080 is measured with a set of six solar observations and the resulting average azimuth is compared to the value established by the Vermont Agency of Transportation (VAT), using the global positioning system. Each of the six sun shots is made by an independent observer, who in this study is represented by a first-year civil engineering student. Three readings were done with the telescope reversed and three were taken with the telescope direct. The local hour angle (LHA) method is used to calculate the astronomic azimuth. The solar constants for the equation of time (EOT), for declination (δ), and for semidiameter (SD) are found in Mica. The astronomic Azimuth 081–080 is 235° 15′ 50″ from the student readings and is 235° 15′ 56″ from VAT data.

The Tonias Algorithm

This paper casts light upon the significance both practical and theoretical of a paper entitled “Spiral Problems for an Electronic Computer,” by Elias C. Tonias, which has acquired wide circulation among computer programmers while remaining unknown to the majority of highway engineers and surveyors. It is the intent of this paper to demonstrate that Tonias's 1965 paper brought into focus the true computational basis of the transition spiral, and to demonstrate the practical usefulness of this vision to the surveyor who, in 1995, often carries a programmable handheld calculator that is perfectly adequate for implementing the Tonias algorithm.

Using the TI-81 to Analyze Sports Data

Our objective is to use the TI-81 calculator to solve several familiar problems, to develop insight into sophisticated mathematical ideas without being encumbered by excess computational difficulty, and Students who know little algebra can observe trends and 636 discuss results to become familiar with the increasingly affordable and user-friendly technology of the hand-held graphing and programmable calculator. In this article, we will analyze several sports examples and obtain and interpret standard statistics for these examples.

Haul‐Unit Performance

Historically, haul-unit speeds have been determined using alignment charts provided by equipment manufacturers. This paper presents a performance equation and outlines a procedure for determining the equation coefficients that determine speeds for off-road haul units. The primary advantage of a performance equation is that it is the ideal algorithm for incorporation into a program for computing haul-unit cycle times for any set of conditions likely to be encountered in the field. The performance equation shares advantages that are inherent when using an equation to determine numerical results. Some additional very desirable features are: (1) The performance equation will take advantage of the power of computers and hand-held programmable calculators; (2) the data can be stored electronically (this type of storage is compact and data is available immediately); (3) calculations for speeds are very fast compared to determining speeds from alignment chart measurements; (4) significant amounts of time will be saved when using the equation in computer programs; (5) calculations are accurate and reliable; and (6) using an equation eliminates the use of performance handbook alignment charts.

A Program for Determining Cocompost Blending Ratios

▪ A program is presented that computes blending ratios for two ingredients of a co-compost. The program is written in the RPN language, requires 61 lines of memory, and will support hand-held programmable calculators, making it suitable for use in the field. Use of this program allows the composter to determine blending ratios quickly and with increased precision and accuracy.

Estimation of ED 50 or LD 50 using a programmable pocket calculator

A program is developed for estimation of median effective dose (ED 50 or LD 50), using the hand-held programmable pocket calculator HP41CV. The well-known Finney's algorithm of probit analysis is used. Input of data is simple, but is restricted to a maximum of 15 groups. The program structure makes use of the technique of indirect addressing for storage, and statistical register manipulation for weighted regression. The ability of the calculator to give sufficiently precise results can be exploited in other similar situations.

Using a Programmable Calculator for Determining Potential Evapotranspiration Rates

Abstract A program is presented allowing the computation of uncorrected potential evapotranspiration (ETp) rates using a low-cost (<$50) hand-held programmable calculator. This program requires the user to supply average local or on-site monthly temperatures. The first part of the program computes the annual heat index and the exponent necessary for ETp determination. The second part of the program computes monthly ETp rates by the Thornthwaite procedure as each average monthly temperature is keyed in. Comparisons of computed ETp rates with measured actual evapotranspiration (ETa) rates of various container-grown nursery crops show good correlation.

A predictive instrument for acute ischemic heart disease to improve coronary care unit admission practices: A potential on-line tool in a computerized electrocardiograph

Each year, 1.5 million patients are admitted to coronary care units (CCUs) for suspected acute ischemic heart disease, but for half of these, the diagnosis is ultimately ruled out. In this study, conducted in the emergency rooms (ERs) of six New England hospitals, the authors sought to develop a diagnostic aid to help ER physicians reduce the numbers of CCU admissions for patients without true acute cardiac ischemia. In phase 1, from data on 2,801 patients, they developed a predictive instrument for use in a handheld programmable calculator, which, based on a mathematical logistic regression formula, computes a patient's probability of having acute cardiac ischemia. In phase 2, a 1-year prospective trial including 2,320 ER patients at the six hospitals, physicians' diagnostic specificity for acute ischemia increased when the probability value determined by the instrument was made available to them (p = 0.002), without a drop in sensitivity. Among patients without acute ischemia, the number of CCU admissions decreased 30% (p = 0.003), without an increase in missed diagnoses of ischemia. The proportion of patients in the CCU without acute ischemia dropped from 44% to 33%. If similar findings were widespread, the use of this predictive instrument could reduce the number of CCU admissions in the United States by more than 250,000 per year. As originally envisioned, the physician could use a pocket-sized programmable calculator to allow quick access to the instrument's probability value, or an ER triage nurse might compute the probability value and write it on the clinical record for the physician's use. However, a much more attractive method would be the integration of the instrument's mathematical formula into a self-interpreting electrocardiograph, the goal of phase 3. Once given the four nonelectrocardiographic clinical variables, a so-programmed machine can compute a given patient's probability of having acute ischemia. Having completed a working prototype, the authors believe that the ease of access in real-time use makes this online electrocardiograph format particularly appealing and the instantiation most likely to promote the predictive intrument's widespread use.

Rapid adjustment of a braced quadrilateral

Abstract Using an orthogonalisation process and by appropriate choice of angular conditions, the condition equations for the adjustment of a braced quadrilateral may be written in such a manner that solution of normal equations becomes unnecessary. This considerably shortens computation time for a manual calculation and makes it possible to write programs which will fit into small hand-held programmable calculators. In addition to this, the miscloses formed prior to computation by this method have the advantage of being statistically independent of one another and may be tested using statistical tables for the presence of gross error.

Design of a ‘rolling’ groundwater control system : Herbert, R Ground EngngV18, N8, Nov 1985, P12–15

A rolling dewatering system is defined as two parallel lines of wells installed at a range to match the movement of the centre of construction for which dewatering is required. As the centre of construction moves forward the first wells installed are gradually shut down as they become more distant from the centre of dewatering. This kind of dewatering installation is useful for construction of sewers, canals, tunnels, etc., where a high water table exists. A program is written for the hand-held programmable t15 calculator, which predicts the performance of such dewatering installations. It is shown that, depending on the diffusivity (t/s) of the aquifer, spacing between wells can be gradually increased as time progresses and economies in dewatering costs can be made. Criteria are developed to a dewatering system required for the construction of a canal in Bangladesh. (Author/TRRL)

Epidemiologic programs for computers and calculators. Simple algorithms for the representation of deterministic and stochastic versions of the Reed-Frost epidemic model using a programmable calculator.

Two programs are described for the emulation of the dynamics of Reed-Frost progressive epidemics in a handheld programmable calculator (HP-41C series). The programs provide a complete record of cases, susceptibles, and immunes at each epidemic period using either the deterministic formulation or the trough analogue of the mechanical model for the stochastic version. Both programs can compute epidemics that include a constant rate of influx or outflux of susceptibles and single or double infectivity time periods.

A Simplified Error Model for Accurate Measurement of High-Frequency Transistor S Parameters

This paper presents a simplified error model for error correction for the measurement of S parameters in high-frequency transistors. The simplification process involves zero order approximation of the transistor parameters S21 and S12, and a one time, rather than successive iteration, approximation of the reflection parameters S11 and S22. The simplified error model can be programmed within the capacity of a medium level handheld programmable calculator.

A PROGRAM TO CALCULATE AQUIFER TRANSMISSIVITY FROM SPECIFIC‐CAPACITY DATA FOR PROGRAMMABLE CALCULATORS

Abstract. A program that will calculate aquifer transmissivity from the specific capacity of a well has been developed for handheld programmable calculators. The program extends the approach of Theis and others (1963) beyond the visual graphical interpolation of transmissivity values from type curves and solves directly a nonlinear equation for transmissivity, using a modified Regula Falsi solution algorithm. The program eliminates errors associated with visual interpolation of transmissivities obtained from type curves, especially for values of small transmissivities, and provides a quick and portable method of obtaining transmissivity values onsite.

Programmable Calculators: Their Use In Lens Design And Analysis

For several years the hand-held programmable calculator has been known to be an attractive tool for solving some relatively simple problems in optical computation, such as general ray tracing, first-order optics, and optical system analysis. The range of application, however, can be extended far beyond this level and includes the semiautomatic design of unsophisticated optical imaging systems such as the air-spaced doublet and the Cooke triplet, for which examples are presented. In view of the limitations in the number of program steps, it is mandatory to implement such programs with utmost economy of use of these program steps and to utilize the inherent properties of these optical systems in order to obtain convergence in the automatic design improvement part of the programs. While the most appropriate application may be in support-ing the teaching of elementary lens design, these calculator programs can be quite helpful if relatively simple optical systems have to be designed without easy access to a large computer facility and associated software.

Microcomputer Programs for the Evaluation of Predictable Long-Term Exposure

Some methods proposed for evaluation of predictable long-term exposure by statistical treatment of workshift exposure values are considered. Predictable long-term exposure is a useful parameter for risk assessment procedures, as it allows the evaluation of workplace hazards by taking into account interday variability of exposure to air contaminants. Statistical calculations required for evaluating predictable long-term exposure may be performed easily by hand-held programmable calculators. The programs reported here are for use with a Texas Instruments TI-59 hand-held programmable calculator equipped with a PC-100 C thermal printer. They are designed for users inexperienced in programming, since an interactive approach has been adopted that helps communication between user and computer.