Spreadsheet Formulas Research Articles

Exception handling in the spreadsheet paradigm

Exception handling is widely regarded as a necessity in languages today and almost every currently used for professional software development supports some form of it. However, spreadsheet systems, which may be the most widely used type of programming language today in terms of number of users using it to create programs (spreadsheets), have traditionally had only extremely limited support for exception handling. Spreadsheet system users range from end users to professional programmers and this wide range suggests that an approach to exception handling for spreadsheet systems needs to be compatible with the equational reasoning model of spreadsheet formulas, yet feature expressive power comparable to that found in other languages. We present an approach to exception handling for spreadsheet system users that is aimed at this goal. Some of the features of the approach are new; others are not new, but their effects on the properties of spreadsheet systems have not been discussed before in the literature. We explore these properties, offer our solutions to problems that arise with these properties, and compare the functionality of the approach with that of exception handling approaches in other languages.

A simple and flexible blood cardioplegia delivery system.

We describe a simple technique for the delivery of high haematocrit blood cardioplegia. The system allows for a user defined, variable concentration of warm, tepid or cold solution to be delivered. The concentration can be varied based upon the pressure regulated flow of blood, and is manipulated by a four variable equation calculated by a spreadsheet formula stored in a hand-held computer. The system provides a very accurate and rapid method of titration and administration of the cardioplegic solution.

Calculation of the Plastic Section Modulus Using the Computer

A simple spreadsheet is presented which calculates the plastic section modulus of structural members. The method consists in dividing the cross section into rectangles and arranging all calculations conveniently into a spreadsheet program. The basic algorithm and the required spreadsheet formulas are given as well as a numerical example.

Application of Hydrophobicity Parameters to Prediction of the Acute Aquatic Toxicity of Commercial Surfactant Mixtures

Abstract Ethoxylated alcohols are the most extensively used nonionic surfactants in detergent products. The application of QSAR to their aquatic toxicity is complicated by the fact that they are multicomponent mixtures, the parent alcohols being often mixtures of isomers and homologues, each one being ethoxylated to varying degrees. A spreadsheet method for calculation of aquatic toxicity of such nonionic surfactant mixtures is presented. The method is based on a combination of the Konemann narcosis QSAR and mixture toxicity equations based on the principle of concentration addition. Log P values used in the spreadsheet calculations are themselves calculated by spreadsheet formulae based on the Leo and Hansch method modified by incorporation of the position dependent branching factor originally applied to linear alkylbenzene sulphonates. Close agreement between calculated and experimental EC50 values (48 hr Daphnia tests) is obtained for a range of ethoxylated alcohols having a diversity of branching patt...

Transforming verbal descriptions into mathematical formulas in spreadsheet calculation

A common subtask in spreadsheet calculation is the transformation of verbal task instructions into spreadsheet formulas. This task can be used to study the relation of imagery to thinking. Research using physics and mathematics problems has indicated that mental transformation from verbal to mathematical representations is not necessarily direct but is intermediated by imagery. Therefore, a human-computer interaction task such as spreadsheet calculation provides a good task environment for analysing mental imagery operations, the role of imagery operations, and the role of intermediate imagery in thinking tasks. Testing the use of imagery in spreadsheet calculations also improves our understanding of representational systems used in this specific task and in user interfaces in general.Four experiments provided different types of evidence for the intermediate imagery hypothesis, which means that subjects do not directly transform verbal instructions into spreadsheet formulas. They first try to code an overall image of the areas referred to by verbal instructions, segment it into suitable fields, and only thereafter do they write down the set of formulas which best extract the information demanded. Typically, the field borders, used in this segmentation are often imagined and are not presented at all in the original verbal task instructions.Intermediate imagery is a relevant notion in discussing the construction of user models because the most important current models, such as GOMS, assume only propositional representations. Also, the use of images should be taken into account in designing spreadsheet packages by providing features which aid analog information processing.

An empirical study of spreadsheet error-finding performance

Several well-founded concerns exist about the integrity and validity of electronic spreadsheets. Thirty CPAs and 30 MBA students volunteered to seek up to two errors planted in each of six spread-sheets to discover if expertise in the domain of accounting and the spreadsheet program would facilitate error-finding performance. Subjects only found, on average, about 55% of the simple, conspicuous errors on the small spreadsheets. As expected, both accounting and spreadsheeting expertise contributed to the subjects' error-finding rate, and those who performed this task with both types of expertise found the largest number of errors in the shortest time. Interestingly, while CPAs were more accurate than non-CPAs in finding accounting-related errors, spreadsheet experts did not outperform novices in finding spreadsheet formula errors. Also, while spreadsheet expertise contributed to greater speed, accounting expertise did not. Future research would further investigate the contribution of spreadsheet expertise to the error-finding task. Practitioners should be aware of the difficulties in finding even simple errors, and develop training programs to facilitate spreadsheet auditors' performance.

Using Projected Lotus ® 123 Spreadsheets to teach Hospitality Accounting Concepts

ABSTRACT A Lotus 123 V2.3 template was designed to follow the format of the Financial Statement Worksheet used in a Financial Accounting for Hospitality Management class. The design followed the format of the text1 as closely as possible so that students could follow the progression of ideas outlined in the text. This template was projected on a screen in the classroom, and printed out in sections, so that students could follow the discussion and take notes without needing to waste time copying text. In the example given, students complete the Trial Balance, and the Adjustments. The Adjusted Trial Balance, Income Statement and Balance Sheet are computed automatically by formula when the adjustments are completed. This suggests that transactional analysis is the key factor in adjustments, as the remaining statements are generated by the spreadsheet formulas.

Finding building shapes that minimize mean trip times

The paper provides a computer-aided means of ensuring that a proposed multiple-floor building is shaped so that the time that people need to move around inside the building is minimized. The metric that captures this is the mean trip time. This is lower, for example, on a square floor than on an elongated floor of the same area. Spreadsheet formulae are provided to identify the number and shape of building floors that minimize mean trip time given building areas, people's walking speed, and lift speed and wait times. In the case of buildings with two floor sizes, the optimal number of floors of each size and the ratio of the two floor areas are also found. These formulae assume evenly distributed trips, i.e. that trip starts and finishes are equally and independently distributed throughout the building. This alleviates the need to obtain interdepartment-trip volumes and department areas. New simple distance theorems form the basis of the formulae. One odd finding is that, in some situations, a multiple-floor building with two floor sizes has a marginally lower mean trip time than a building of equal area in which all the floors are the same size.