Compositions and fuzzy compositions in decision-making models

In decision-making models, the compositions (Aitchison, 1986) are employed in various forms. They can represent the normalized weights of criteria in multiple-criteria decision-making models, or the probabilities of states of the world in the models of decision making under risk. The normalized weights express the relative information about the importance of criteria, while the probabilities reflect the expected incidence of the states of the world. The compositions are also the evaluations of objects according to their contributions to a common goal. This paper addresses the situation when the compositions are set expertly. This is the typical way of obtaining the normalized weights of criteria. Various methods of setting the weights were introduced in order to properly reflect the preferences of the decision maker. Direct methods where the decision maker sets the weights directly can be distinguished from indirect ones, e.g., the method of pair-wise comparison, or Saaty’s AHP

Influence of Green IT on Consumers’ Buying Behavior of Personal Computers: Implications from a Conjoint Analysis

The increasing attention towards the environmental impact of IT (Information Technology) demands reorientation from IT hardware and service organisations. Consumers are more than ever sensitive about the environmental impact of products and services they buy. Environmental attributes therefore play an important role in the buying process. While the concept of Green IT has been primarily researched from the corporate perspective, the consumer perspective has widely been neglected. The purpose of this paper is to evaluate the influence of Green IT attributes of PCs (Personal Computers) on the buying behaviour of consumers. As a contribution to the ongoing discussion of Green IT, we provide marketing data from 500 participants on the importance of Green IT using conjoint and cluster analysis. It is shown that the market share for Green IT PCs could be up to 26.6%. Especially female customers value environmentally friendly attributes. Thereafter, we draw recommendations for the marketing mix of IT hardware and service organisations. The results should provide researchers and practitioners with new insights and measures about the relevance and application of Green IT in the scope of PCs

A First Step Towards Behavioral Coaching for Managing Stress: A Case Study on Optimal Policy Estimation with Multi-stage Threshold Q-learning

Psychological stress is a major contributor to the adoption of unhealthy behaviors, which in turn accounts for 41% of global cardiovascular disease burden. While the proliferation of mobile health apps has offered promise to stress management, these apps do not provide micro-level feedback with regard to how to adjust one's behaviors to achieve a desired health outcome. In this paper, we formulate the task of multi-stage stress management as a sequential decision-making problem and explore the application of reinforcement learning to provide micro-level feedback for stress reduction. Specifically, we incorporate a multi-stage threshold selection into Q-learning to derive an interpretable form of a recommendation policy for behavioral coaching. We apply this method on an observational dataset that contains Fitbit ActiGraph measurements and self-reported stress levels. The estimated policy is then used to understand how exercise patterns may affect users' psychological stress levels and to perform coaching more effectively

TQM and labour productivity in Jordanian industrial companies

Reports on research to determine the degree of application of total quality management (TQM) philosophy and practices in industrial corporations in Jordan. Uses primary and secondary empirical data to examine the link between TQM and labour productivity. Survey responses were classified into two groups: high-TQM implementation and low-TQM implementation. Found that mean labour productivity measurements for high-TQM companies were significantly higher than for low-TQM companies over the period 1993-1998. Also, mean growth rates of labour productivity measurements for companies with high-level TQM were higher than for those with low-level TQM during this period. Regression analysis demonstrated a statistically significant positive relationship between TQM and labour productivity

Developing an optimum maintenance policy by life cycle cost analysis - a case study

This paper focuses on developing maintenance policies for critical assets to improve the production performance based on life cycle cost (LCC) analysis. A general approach is adopted for conducting the LCC analysis. The investigation is based on a case study to demonstrate how an optimum maintenance policy is determined. The relevant LCC structure in the case study is defined for the decision process which involves determination of the optimum life, repair limit and selection of materials, and trade-off between repair and replacement. The LCC analysis is based on statistical data modelling which facilitates decision-making on the optimal replacement of an asset and its remaining life. Based on the optimization and remaining life criterion, the optimal maintenance policy can be made. The results obtained from this case study include selection of the best lining material for use, determination of the optimal time for refractory lining replacement, the hot repair sequence required for maintaining the optimum condition and the repair limit for doing cold repairs before replacement, for one type of electric arc furnaces used in the steel industry

Estimating the sample size of sham-controlled randomized controlled trials using existing evidence [version 2; peer review: 2 approved].

Background: In randomized controlled trials (RCTs), the power is often 'reverse engineered' based on the number of participants that can realistically be achieved. An attractive alternative is planning a new trial conditional on the available evidence; a design of particular interest in RCTs that use a sham control arm (sham-RCTs). Methods: We explore the design of sham-RCTs, the role of sequential meta-analysis and  conditional planning in a systematic review of renal sympathetic denervation for patients with arterial hypertension. The main efficacy endpoint was mean change in 24-hour systolic blood pressure. We performed sequential meta-analysis to identify the time point where the null hypothesis would be rejected in a prospective scenario. Evidence-based conditional sample size calculations were performed based on fixed-effect meta-analysis. Results: In total, six sham-RCTs (981 participants) were identified. The first RCT was considerably larger (535 participants) than those subsequently published (median sample size of 80). All trial sample sizes were calculated assuming an unrealistically large intervention effect which resulted in low power when each study is considered as a stand-alone experiment. Sequential meta-analysis provided firm evidence against the null hypothesis with the synthesis of the first four trials (755 patients, cumulative mean difference -2.75 (95%CI -4.93 to -0.58) favoring the active intervention)). Conditional planning resulted in much larger sample sizes compared to those in the original trials, due to overoptimistic expected effects made by the investigators in individual trials, and potentially a time-effect association. Conclusions: Sequential meta-analysis of sham-RCTs can reach conclusive findings earlier and hence avoid exposing patients to sham-related risks. Conditional planning of new sham-RCTs poses important challenges as many surgical/minimally invasive procedures improve over time, the intervention effect is expected to increase in new studies and this violates the underlying assumptions. Unless this is accounted for, conditional planning will not improve the design of sham-RCTs

Information seeking behaviour of parents of paediatric patients for clinical decision making: the central role of information literacy in a participatory setting.

Introduction. This study investigated the information seeking behaviour and needs of parents of paediatric patients and their motives for seeking Internet-based information. Method. A questionnaire survey of 121 parents was conducted in a paediatric clinic of a Greek university hospital. Analysis. The data were analysed using SPSS; descriptive statistics were used to summarise the data and non-parametric Mann-Whitney U and Kruskal-Wallis test statistics were performed to identify differences in reported information seeking behaviour. Results. Parents sought further information than that provided by their paediatrician and searched on the Internet to reduce their anxiety and cope better with their children's medical condition. The Internet was the second most important information source used after the paediatrician. The main obstacles parents encountered were the volume and unreliability of Internet health information and the infrequency of visits to the doctor. Conclusions. Informed participation of patients and paediatricians in clinical shared decision-making requires the development of information literacy in both parties. Health information professionals may act as information literacy instigators and educators for parents and paediatricians by means of offering information literacy prescriptions and other information decision aids

Is the Thoracolumbar Injury Severity Score (TLISS) still a good base for the education of residents in Orthopaedics and Traumatology?

ABSTRACT Introduction. Thoracolumbar spinal injuries indicated for surgical intervention specify the necessity of intervention within 24 hours. The traumatologists working in a structure without a Spinal Unit must be able to evaluate such injury and set indications for surgical treatment, that is, nonoperative treatment. The purpose of this study is to evaluate if Thoracolumbar Injury Severity Score (TLISS) is still a good base for the classification of thoracolumbar spinal injuries and to give a correct indication for nonoperative, that is, surgical treatment. Patients and Methods. Six Orthopaedics and Traumatology residents from Siena (Italy), five Orthopaedics and Traumatology residents from the Clinical Centre of Banja Luka (Bosnia and Herzegovina) and five Orthopaedics and Traumatology residents from the Alta Val d’Elsa Hospital, Siena (Italy) were presented 24 clinical cases from professional literature where the following data were indicated: patient’s age, neurological conditions, description of the injury, mechanism of the injury and radiological findings (RTG, MR). The abovementioned 24 patients were chosen from the literature based on the injuries mostly seen by an orthopaedist with a lack of experience in the problems of spinal column trauma (low energy trauma, with partial or without neurological impairments, with the TLISS score of 4). The residents from the three groups had to classify all patients according to the TLISS score and to define the most appropriate method of treatment-conservative or surgical, and after that, all classifications, as well as the therapeutic decisions, were compared. The statistical methods used in this study include: statistical significance, reliability (P<0.05), the validity of the decision, the percentage of accuracy and Cohen’s kappa coefficient. The best results in evaluation of the mechanism of the injury were demonstrated by the group of doctors from the Orthopaedic Hospital with an accuracy of 78.8% (P<0.05) and with an average correlation (K = 0.598). The best description of the injury was presented by the doctors from Siena with 87% accuracy (P<0.05) and with correlation (K=0.749). The doctors from Siena responded best at evaluating the neurological status with 97.6% accuracy (P<0.05) and with correlation (K=0.936). The assessment of the injury of the PCL residents from Siena was 64.7% accurate (P<0.05) with correlation (K=0.426). The total TLISS score was best calculated by the residents of Siena with 82% accuracy (P<0.05) and correlation (K=0.718). The most appropriate therapeutic decision was made by the residents from Siena with 80.3% accuracy (P<0.05) and with correlation (K =0.707). Conclusion. Currently, the Denis classification and the AO classification are the most widely used classification algorithms for the fractures of thoracolumbar spine but some defects have also been identified in both of them. The value of TLISS evaluation is by the three groups of residents in presented 24 patients from the professional literature. Significant differences in accuracy were found in defining a real damage of the spinal cord at the level of the cauda equina. The evaluation of the integrity of the posterior longitudinal ligament by the radiography is of low accuracy

Normative reference values for estimated cardiorespiratory fitness in apparently healthy British men and women.

Objectives To develop normative reference standards for estimated cardiorespiratory fitness (eCRF) measured from treadmill-based incremental exercise testing in ~12 000 British men and women. Methods Cross-sectional study using retrospectively collected eCRF data from five preventative health screening clinics in the United Kingdom. Reference centiles were developed using a parametric approach by fitting fractional polynomials. We selected the 'best' powers by considering both the smallest deviance, and clinical knowledge from the following set of a priori decided powers (-2,-1,-0.5, 0, 0.5,1,2,3). A series of fractional polynomials (FPs) were investigated with three-parameters (median, standard deviation and skewness). The following reference centiles were plotted (3, 5, 10, 25, 50, 75, 90, 95, 97). Results We included 9 204 males (median [25th,75th centiles] age 48 [44, 53] years; BMI 27 {25, 29] kg∙m-2; peak VO2 36.9 [30.5, 44.7] ml∙kg-1∙min-1) and 2 687 females (age 48, [41, 51] years; BMI 24 {22, 27] kg∙m-2; peak VO2 36.5 [30.1, 44.8] ml∙kg-1∙min-1) in our analysis to develop the normative values. Conclusion Reference values and nomograms for eCRF were derived from a relatively large cohort of preventative health care screening examinations of apparently healthy British men and women. Age- and sex-specific eCRF percentiles were similar to data from international cohort studies. The adoption of submaximal exercise testing protocols reduces individual risk when exercise history is unknown and testing is conducted in a community-based setting. Our findings can be used by health professionals to help guide clinical decision making