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Article
Publication date: 28 November 2019

Yilmaz Hatipkarasulu

This paper aims to present a graphical comparison method for construction schedules, which illustrates the differences for each individual activity. The method overlays the…

Abstract

Purpose

This paper aims to present a graphical comparison method for construction schedules, which illustrates the differences for each individual activity. The method overlays the observed differences on a bar chart creating a representation of whether each activity is ahead, on or behind schedule at a given date.

Design/methodology/approach

The method is implemented using a Microsoft Project add-in (plug-in). The paper demonstrates the method and its potential uses with three illustration cases: a time impact analysis, an alternative analysis for the selection of subcontractors and a multi-baseline analysis of an as-built schedule.

Findings

The cases included in the paper show that the proposed method uses a simplified and familiar attribute comparison for each activity in a schedule. The method affords flexibility in presenting differences between schedules such as the start/finish dates or duration. As the method does not rely on a specific software application or analysis method, it can be implement to different software applications as well as performance or delay analysis techniques. The method also makes it possible to present multiple and selective baseline comparisons overlaid on an updated or as-built schedule.

Originality/value

The method graphically presents a comparison of start dates, durations and finish dates for each activity that can be integrated with any schedule. The method can be used for forensic analysis as well as project control measures during construction. As the method does not rely on any specific performance or delay calculation method, it can be applied to any forensic analysis technique and delay analysis.

Details

Construction Innovation , vol. 20 no. 1
Type: Research Article
ISSN: 1471-4175

Keywords

Article
Publication date: 5 December 2016

Razika Ihaddadene, Nabila Ihaddadene and Marouane Mostefaoui

The purpose of this paper is to analyze and compare four numerical methods to estimate the most suitable one which describes wind speed distribution of M’Sila, a province of…

Abstract

Purpose

The purpose of this paper is to analyze and compare four numerical methods to estimate the most suitable one which describes wind speed distribution of M’Sila, a province of northern Algeria.

Design/methodology/approach

The site chosen in this investigation is characterized by calm winds; in this case, the appropriate wind speed distribution is that of hybrid Weibull.

Findings

The four numerical methods used in the present paper are the maximum likelihood method, the graphical method, the moment method and the energy pattern factor method. The hybrid Weibull distributions using the abovementioned approaches are compared with the measured data via three statistical parameters, namely, the correlation coefficient, the root mean square error and the Chi-square error.

Originality/value

The obtained results showed that the moment method is the suitable one in describing month and annual wind speed hybrid Weibull parameters of this region.

Details

World Journal of Engineering, vol. 13 no. 6
Type: Research Article
ISSN: 1708-5284

Keywords

Book part
Publication date: 30 May 2018

Francesco Moscone, Veronica Vinciotti and Elisa Tosetti

This chapter reviews graphical modeling techniques for estimating large covariance matrices and their inverse. The chapter provides a selective survey of different models and…

Abstract

This chapter reviews graphical modeling techniques for estimating large covariance matrices and their inverse. The chapter provides a selective survey of different models and estimators proposed by the graphical modeling literature and offers some practical examples where these methods could be applied in the area of health economics.

Article
Publication date: 1 October 2018

Peter Madzík and Vera Pelantová

Product verification and validation are integral to quality management. Product verification means verifying the conformity between a product’s actual and planned characteristics…

Abstract

Purpose

Product verification and validation are integral to quality management. Product verification means verifying the conformity between a product’s actual and planned characteristics whereas validation means determining whether and to what extent it satisfies customers’ requirements. One of the key forms of product validation is testing with a group of customers. The purpose of this paper is to introduce a graphical method of product validation based on the Kano model.

Design/methodology/approach

The approach is based on a proposed method for categorising requirements based on a Kano questionnaire and then applies this method for the validation of a product – a website. The proposed method is based on three steps: graphical determination of requirements in a Kano model; determination of requirement fulfilment degree and prioritisation of corrective measures and improvements.

Findings

The study opens space for discussion of the potential for improving a product and methods for identifying critical faults in products. The proposed method also permits an assessment of the potential effectiveness of an improvement because it is able to quantify the effect of the product on the consumer resulting from a given quantity of effort. A case study demonstrated that the resulting priority of corrective measures and improvements was affected not only by the level of fulfilment of the requirements but also by the type, the most critical being non-fulfilment of must-be requirements.

Research limitations/implications

The requirement curves are based on a verbal assessment of satisfaction in two states – if the requirement were fulfilled and if it were not fulfilled. The values of the start and end points may not be precise and could be affected by the natural character of subjective variables.

Practical implications

The proposed method is particularly suited to the initial testing of a product that is intended to lead to measures to eliminate customer dissatisfaction or increase their satisfaction – that is, to improve the product. The method also permits an assessment of the extent to which customers feel that their expectations have been satisfied and the effect that will be felt if the organisation decides to increase fulfilment.

Originality/value

The Kano model has not yet been applied to product validation, although it contains all the information necessary for this task. Knowing how satisfied customers are is an important part of product validation. At the same time, knowing a mechanism for “creating” this satisfaction is also very valuable information.

Details

International Journal of Quality & Reliability Management, vol. 35 no. 9
Type: Research Article
ISSN: 0265-671X

Keywords

Article
Publication date: 1 March 1998

KRIS G. MATTILA and DULCY M. ABRAHAM

Since the early 1960s, there have been different techniques to schedule linear projects, but for the most part, these have been overshadowed by the critical path method (CPM)…

Abstract

Since the early 1960s, there have been different techniques to schedule linear projects, but for the most part, these have been overshadowed by the critical path method (CPM). Recently, there has been renewed interest in linear scheduling and in adapting some of the CPM techniques to linear scheduling. This necessitates a review of the research in the area of linear scheduling. The present paper provides an overview of linear scheduling, discusses the different approaches that have been used and expresses new avenues for research in the area of resource levelling of linear schedules.

Details

Engineering, Construction and Architectural Management, vol. 5 no. 3
Type: Research Article
ISSN: 0969-9988

Keywords

Article
Publication date: 22 May 2009

Ali Uyar

The purpose of this study is to: discover the nature and extent of the use of graphs by the top 100 companies listed on the Istanbul Stock Exchange (ISE), Turkey; compare patterns…

1649

Abstract

Purpose

The purpose of this study is to: discover the nature and extent of the use of graphs by the top 100 companies listed on the Istanbul Stock Exchange (ISE), Turkey; compare patterns of graphic disclosure across industries; and assess the correlation between graphic disclosure and the variables: open‐to‐public ratio, firm performance, firm size, and firm profitability.

Design/methodology/approach

The methodology of the study is content analysis of annual reports of the corporations listed on the ISE for the year 2006.

Findings

The major findings of the study are as follows. About 75 percent of the companies include graphs in their annual reports. The average number of graphs contained in annual reports is 8.6. Financial companies have the highest graph usage per annual report (10.16). The most widely graphed financial variables are sales and earnings; however, earnings per share and dividend per share variables are graphed by none of the companies. There is no correlation between graphic disclosure and the variables open‐to‐public ratio and firm performance. There is a significant positive correlation between graphic disclosure and the variables firm size and profitability.

Research limitations/implications

The findings of this paper are based on the study conducted on the ISE. The results are not generaliseable to non‐listed companies.

Originality/value

The paper is one of the rare graphical studies conducted in developing countries. Moreover, the study is the first of its kind that has ever been conducted in Turkey.

Details

Managerial Auditing Journal, vol. 24 no. 5
Type: Research Article
ISSN: 0268-6902

Keywords

Article
Publication date: 18 July 2019

Zahid Hussain Hulio and Wei Jiang

The purpose of this paper is to investigate wind power potential of site using wind speed, wind direction and other meteorological data including temperature and air density…

Abstract

Purpose

The purpose of this paper is to investigate wind power potential of site using wind speed, wind direction and other meteorological data including temperature and air density collected over a period of one year.

Design/methodology/approach

The site-specific air density, wind shear, wind power density, annual energy yield and capacity factors have been calculated at 30 and 10 m above the ground level (AGL). The Weibull parameters have been calculated using empirical, maximum likelihood, modified maximum likelihood, energy pattern and graphical methods to determine the other dependent parameters. The accuracies of these methods are determined using correlation coefficient (R²) and root mean square error (RMSE) values.

Findings

The site-specific wind shear coefficient was found to be 0.18. The annual mean wind speeds were found to be 5.174 and 4.670 m/s at 30 and 10 m heights, respectively, with corresponding standard deviations of 2.085 and 2.059. The mean wind power densities were found to be 59.50 and 46.75 W/m² at 30 and 10 m heights, respectively. According to the economic assessment, the wind turbine A is capable of producing wind energy at the lowest value of US$ 0.034/kWh.

Practical implications

This assessment provides the sustainable solution of energy which minimizes the dependence on continuous supply of oil and gas to run the conventional power plants that is a major cause of increasing load shedding in the significant industrial and thickly populated city of Pakistan. Also, this will minimize the quarrel between the local power producer and oil and gas supplier during the peak season.

Social implications

This wind resource assessment has some important social implications including decreasing the environmental issues, enhancing the uninterrupted supply of electricity and decreasing cost of energy per kWh for the masses of Karachi.

Originality/value

The results are showing that the location can be used for installing the wind energy power plant at the lower cost per kWh compared to other energy sources. The wind energy is termed as sustainable solution at the lowest cost.

Details

International Journal of Energy Sector Management, vol. 14 no. 1
Type: Research Article
ISSN: 1750-6220

Keywords

Article
Publication date: 21 August 2013

Y. Chang

Goldbach conjecture of prime numbers is one of the unsolved mathematical problems. Many trial solutions appeared in the literature, but so far none has been accepted by the…

Abstract

Goldbach conjecture of prime numbers is one of the unsolved mathematical problems. Many trial solutions appeared in the literature, but so far none has been accepted by the mathematics societies. This paper describes a graphical method devised by me to explain the mystery of the said conjecture. My method based on the teachings of analytical geometry using a rectangular coordinate frame with even numbers as ordinates and prime numbers as abscissas. Straight lines with 45 degree slop and intercepets of varying prime numbers on the ordinate are drawn to meet all the vertical straight draw grom the abscissas. These diagonal lines are designated as separation lines and identified by its intercept number. The intersection of vertical abscissa line, the separation line and a horizontal line drawn from the ordinates shows the relationship of an even number and its pair of prime numbers. These intersections vividly appear on the horizontal even number line and can be easily seen. This method is a graphical version of binary combination of prime numbers and can locate the prime-pairs of any even nuber by drawing a family of separation lines.

Details

World Journal of Engineering, vol. 10 no. 4
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 1 February 2003

Stella So and Malcolm Smith

Accounting information is essentially multivariate and the relationships among variables may be difficult to establish. Differing multivariate information presentation methods may…

3494

Abstract

Accounting information is essentially multivariate and the relationships among variables may be difficult to establish. Differing multivariate information presentation methods may impact on the quality of the decisions made by users. Existing studies in this area have given scant attention to differences between individual users, despite earlier suggestions from the second author of this paper that both gender and personality might impact on information processing. This study focuses on the interaction of the decision maker (addressing issues of gender, personality, cognitive style and ability) with the data presentation method (including tables, graphical and pictorial methods) in the management decision making process. The paper reports on experiments conducted with respondents of varying degrees of accounting sophistication, using a failed/non‐failed decision environment. Results provide support for the use of graphical and pictorial methods as means of representing data for this decision task, while also identifying the influence of gender, spatial ability and tolerance of ambiguity. These findings have implications for the matching of information presentation with the characteristics of the decision maker in management decision making.

Details

Managerial Auditing Journal, vol. 18 no. 1
Type: Research Article
ISSN: 0268-6902

Keywords

Article
Publication date: 20 May 2019

Elie Bertrand Kengne Signe, Abraham Kanmogne, Guemene D. Emmanuel and Lucien Meva’a

The purpose of this paper is contribution to estimate the potential of wind energy in Douala in Cameroon, by modeling and predicting the regime of wind. The paper deals with the…

Abstract

Purpose

The purpose of this paper is contribution to estimate the potential of wind energy in Douala in Cameroon, by modeling and predicting the regime of wind. The paper deals with the analysis and comparison of seven numerical methods for the assessment of effectiveness in determining the parameters for the Weibull distribution, using wind speed data collected at Douala International Airport in Cameroon, in the period from September 2011 to May 2013, obtained by meteorological equipment belonging to the Laboratory of Energy Research of the Institute of Geological and Mining Research.

Design/methodology/approach

By using ANOVA, root mean square error and chi-square tests to compare the proposed methods, this study aims to determine which methods are effective in determining the parameters of the Weibull distribution for the available data, in an attempt to establish acceptable criteria for better usage of wind power in Douala, which is the economic capital and ought to have prominence in the use of renewable sources for electricity generation in Cameroon.

Findings

The study helps to determine that moment, empirical and energy pattern factor methods used to determine the shape parameter k and the scale parameter c of the Weibull distribution present a better curve fit with the histogram of the wind speed. This fact is clearly validated by means of the statistical tests. But, all the seven methods gave excellent performance. Then, k reaching levels ranging from 3.5 to 5.5 and c range from 1.7 to 2.4.

Originality/value

Then as far as we are concerned, for a significant contribution, it could be more effective to have a model for prediction of wind characteristics using wind data collected per hour, one at least three years. A comparison of results obtained from lots of other methods (seven in this case) is necessary before an efficient discussion. Standard deviations and errors between measured and predicted data must also be presented.

Details

International Journal of Energy Sector Management, vol. 13 no. 4
Type: Research Article
ISSN: 1750-6220

Keywords

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