Assessing determinants of desirable ES impact on end-user jobs

To increase the likelihood of experts systems' success it is useful to identify the more important determinants to focus managerial attention and resources. Seven major determinants of expert system success, here defined as desirable impact of the system on users' jobs, have been identified from the literature. DuPont's collection of expert systems (ES) provided the sample of 114 applications used in this study. The results corroborate much of what has been proposed in the literature, except for user characteristics which have been found to have no significant relationship to the measure of success. Based on the results, some recommendations are made to expert system development managers, including: (1) besides the recommendations already proposed in the literature, managers should deliberately seek to deal with important, large, labour intensive and complex problems which are important to the organization; (2) the selection of a development shell with the characteristics described in this study, and which matches the problem at hand is an important determinant of success; and (3) even though the primary source of knowledge is one or more domain experts, user involvement in the development process remains an important factor for ES to have a desirable impact on the latter's jobs.     

Empirically assessing factors related to DSS benefits

This paper reports the results of a field study surveying 201 US business managers to test the relationship between decision support systems (DSS) benefits and a list of factors expected to affect them. DSS benefits considered are: decision quality, competitive edge, improved communication, cost reduction, increased productivity, time savings, overall satisfaction, overall cost effectiveness and total benefits. The determinants of DSS benefits fall into four broad categories encompassing attributes of the industry (strategic position and degree of competition), the organization (size of organization, task structuredness, frequency of use, quality of training, organization support and vendor support), the DSS (timeliness of output, completeness of output, accuracy of output, relevance of output, flexibility, range of alternatives and user-friendliness) and of the DSS user (age of user, experience with DSS, experience on job, education level, attitude of user and expectations of user). Correlation coefficients and incremental R square measures (stepwise regression) show that much of the variance (52-84%) in each of the benefits can be explained by the factors included in the study. Based on the results, managerial recommendations on how to proceed to increase DSS benefits are presented.     

Assessing the quality of institutional DSS

Effectively assessing decision support systems (DSS) quality has long been a difficult challenge to developers and users. Despite the difficulty, the need to justify substantial investments in DSS projects motivates academics and practitioners alike to attempt continuously to improve quality assessment procedures and methods. Institutional DSS are likely to exacerbate the need for quality assessment because they tend to be larger and more expensive than personal DSS. Institutional DSS, by definition, are used by many people throughout the organization. It is very likely, in such cases, that users will have different perspectives, objectives and expectations from the system. Discussion and comparison of existing methods to assess DSS quality are presented, followed by a proposal for the use of the analytical hierarchy process (AHP) method as a more viable alternative for institutional DSS quality assessment. A case study is used to demonstrate the use of AHP for institutional DSS quality assessment in practice.     

Cohesive design of personalized Web applications

Good software engineering practices, such as separating concerns and identifying patterns, simplify the critical design decisions in building personalized Web applications. The authors use the object-oriented hypermedia design method (OOHDM) for constructing customized Web applications. Incorporating well-known object-oriented design structures and techniques, OOHDM produces flexible Web application models. Designers can add personalized behavior to these models with minimal code manipulation, and reasoning over design objects yields better insight into the personalization process. Although this article casts the discussion in terms of the OOHDM primitives, the ideas presented can be easily applied to other design approaches, such as WebML     

Novel transformer connection to improve current sharing inhigh-current DC rectifiers

This paper presents a novel, nonconventional family of power converters for low-voltage, high-current applications based on a peculiar series connection of the primary windings. On the secondary side, all the semiconductors are directly connected in parallel without resorting to the use of interphase transformers or any other current sharing means. The series connection of the primaries ensures current sharing while a zigzag arrangement provides the desired pulse number     

Effects of citrate‐enriched bicarbonate based dialysate on anticoagulation and dialyzer reuse in maintenance hemodialysis patients

Systemic anticoagulation with unfractionated heparin is commonly used in maintenance hemodialysis (HD), but it increases the risk of bleeding complications. We investigated whether the use of citrate‐enriched bicarbonate based dialysate (CD) would reduce systemic anticoagulation without compromising the efficacy of reprocessed dialyzers. This is a crossover study in which half of a total of 30 patients initially underwent HD with acetate‐enriched bicarbonate based dialysate and a standard heparin dose of ～100 IU/kg (Treatment A), whereas the remaining patients were treated with CD and a 30% reduced heparin dose (Treatment B). After 12 consecutive HD sessions in each treatment, the dialysate and heparin doses were reversed, then followed for another period of 12 HD sessions. The two treatment phases were split by a washout period of six HD sessions using acetate‐enriched bicarbonate based dialysate and standard heparin dose. Systemic anticoagulation was higher in Treatment A. The activated partial thromboplastin time at the end of HD session was 68 ± 36 seconds in Treatment A and 47 ± 16 seconds in Treatment B (P = 0.005). Sixty‐eight percent of the dialyzers remained adequate until the 12th use in Treatment A and 61% did so in Treatment B (P = 0.63). Patients had three and 24 cramps episodes during Treatment A and B, respectively (P < 0.001). Nine and 26 symptomatic intradialytic hypotension episodes were seen in Treatment A and B, respectively, (P = 0.003). In conclusion, the use of CD had a favorable effect on anticoagulation in the extracorporeal circuit in patients on maintenance HD, but it was also associated with more hypotension and cramps.     

The Benefits and Problems of User Computing

The continuing growth of user computing can be attributed primarily to advancements in technology, corresponding price reductions, and user dissatisfaction with the MIS response to their information requirements. As a result, users are turning to personal computers and information centers as computing alternatives. This situation can benefit all concerned, but some caveats must be heeded.     

Life cycle assessment of a semi-indirect ceramic evaporative cooler vs. a heat pump in two climate areas of Spain

The aim of this study is to compare the environmental profile of a semi-indirect ceramic evaporative cooler (SIEC) with low environmental impact and heat pipe (HP) heat-exchanger battery with that of a Split class heat pump. The comparison is carried out for two different climate areas in Spain, one a continental or inland climate (Valladolid) and the other representative of a Western European climate (Bilbao). The environmental and economic study is conducted using life cycle assessment (LCA) with two software tools provided by SimaPro® 7.1 LCA suite (Eco-indicator‘99® and EPS 2000®). After the LCA sensitivity analysis results it can be clearly inferred that the major contribution to the categories of damage in both facilities (SIEC and heat pump) is the class of abiotic resources, followed by human health. The high contribution to environmental impact of the evaporative condenser, part of the SIEC-HP, should also be emphasized. With regard to the heat pump, electricity proves to be the main environmental burden, followed by the pump infrastructure, in which the compressor, the external battery, the external fan and the connection have the highest impacts, respectively.