A descriptive model of success for computer-based information systems

This article presents a model of the success of computer-based information systems. We hypothesize that the following variables influence the success of the system: involvement of managers in computerization projects: higher-level managerial support; the technical quality of the system; personal factors; the attitude of managers towards EDP personnel and the attitude of managers towards the computerized system. The research finds that the manager's attitudes to computerization are related to all but the last two.Certain classes of variables are difficult to relate to the success of the system (for example, personal factors). If the evidence for the model is considered strong enough to warrant action, the organization should concentrate on several key variables: high quality of the system; good management support, and good training and management involvement.The results of our research should provide better understanding of the variables associated with the success of a computer-based system.     

Robust multi-variable identification: Optimal experimental design with constraints

Model identification for use in the design of multi-variable controllers should utilize an experimental design that optimizes the resulting robust control stability and performance, irrespective of the eventual controller structure or tuning. Previous research has shown that a key factor is to identify a steady-state gain matrix with minimal mismatch in the multi-variable gain directionality. In particular, for ill-conditioned systems, precise estimation of the weak process directions is essential.This research extends prior work to provide two alternative design formulations for robust multi-variable identification that allow seamless inclusion of any linear inequality constraints in the inputs, outputs or combinations thereof. These designs, based on D-optimality theory, produce highly correlated input sequences, and accommodate the input and output constraints by using highly unbalanced replications at the various input condition support-points.The superior effectiveness of the proposed designs over prior methods in the literature is demonstrated on a two-input, two-output binary distillation case study. In addition, the seamless extension of the method to higher-order systems is exhibited via a four-input, four-output fluid catalytic cracking example.Uncertainty in the prior estimate of the steady-state gain matrix and in design implementation is addressed in both of the proposed formulations. Furthermore, the second formulation provides a single tuning parameter to balance the efficacy of robust identification versus minimizing sensitivity to uncertainty. Finally, guidelines are presented for the extension of these methods to non-square systems.     

Enduring involvement with wine: predictive model and measurement

This exploratory study identifies the dimensions of enduring involvement with wine. This article outlines the conceptualisation and measurement of enduring involvement of consumers with wine in regard to its value order in the hierarchy of needs. A convenience sample yielded 140 useable surveys after questionnaires were administered to pre-qualified consumer respondents. Data were analysed using the Predictive Analytics SoftWare statistical software package and its add-on feature, AMOS 18. It was found that wine consumers exhibit varying dimensions of enduring involvement according to the characteristics of the hierarchical order of need. The dimensions of enduring involvement identified to be associated with wine as a social and esteem value order product were: pleasure/interest, wine-related lifestyle/enjoyment and self-image/sign value. We conclude that enduring involvement is the more important of the two variants (situational and enduring) of the involvement paradigm. When harnessed by wine marketers, this may therefore boost sales and customer loyalty. Marketers need to know the drivers of wine consumers in relation to the product they buy. This will help in communicating the best strategies to adopt for consumers and how they are applied.     

Latent Variable Model Predictive Control (LV-MPC) for trajectory tracking in batch processes

Latent Variable Model Predictive Control (LV-MPC) algorithms are developed for trajectory tracking and disturbance rejection in batch processes. The algorithms are based on multi-phase PCA models developed using batch-wise unfolding of batch data arrays. Two LV-MPC formulations are presented, one based on optimization in the latent variable space and the other on direct optimization over a finite vector of future manipulated variables. In both cases prediction of the future trajectories is accomplished using statistical latent variable missing data imputation methods. The proposed LV-MPCs can handle constraints. Furthermore, due to the batch-wise unfolding approach selected in the modeling section, the nonlinear time-varying behavior of batch processes is captured by the linear LV models thereby yielding very simple and computationally fast nonlinear batch MPC. The methods are tested and compared on a simulated batch reactor case study.     

VISTAnet and MICA: medical applications leading to the NCIH

Medical applications employing an ATM network have been under development with the VISTAnet and Medical Information Communication Application (MICA) trials in North Carolina. The extraordinary switching and transport capabilities of ATM networks represent an enabling technology for many health care applications. VISTAnet and MICA have provided early experience with the networks to support such applications. The NCIH will provide a public ATM platform to expand such efforts throughout North Carolina, and will ultimately provide universal access to a myriad of public information services. VISTAnet has enabled studies in high-speed computation and networking, along with real-time multidimensional imaging. As a result, a new dynamic radiation therapy planning process has been developed that promises to advance the state of the art for radiation treatment. This articles describes the early medical prototype applications of VISTAnet and MICA, and discusses some of the emerging medical applications to be implemented in the NCIH, based on the information learned in the VISTAnet and MICA trials     

Secondary sexual development (Masculinity) of bovine males: 2. Influence on certain meat quality characteristics

Differences in meat quality traits between bulls with secondary sexual development (bulls(+), n = 10), those without this development (bulls(−), n = 10) and steers (n = 10) were investigated. All animals had no permanent incisors (A-age group). Significant differences (P < 0·05) between bulls(+) and bulls(−) were found for the cooking loss percentage of the M. splenius (27·83% versus 31·11%, respectively), iron content of the M. splenius (56·02μg/g versus 49·43μg/g, respectively) and total collagen content of the M. splenius (3·74 versus 4·73 measured as Hyp N/Tot N x 1000, respectively). Drip loss of the wingrib cut (4·01% versus 5·18%, respectively) was also significantly different between bulls(+) and bulls(−). For the M. longissimus thoracis, no significant (P < 0·05) differences in any of the quality-indicating parameters investigated could be found. It is concluded that the M. splenius can be used as an indicator muscle for masculinity, based on meat quality attributes. This is supported by the correlation coefficients obtained between masculinity and the intramuscular collagen content of the M. splenius (r = −0·55) and the iron content of the M. splenius (r = 0·46). For all the other quality attributes investigated, non-significant (P > 0·05) differences between the three sex condition groups were found. It is concluded that the influence of masculinity on meat quality traits of young bulls is of little practical importance in a classification and grading system.     

Secondary sexual development (Masculinity) of bovine males: 1. Influence on carcass composition, cutability, economic value and certain muscles

Differences in carcass composition, cutability, economic value of the carcass and distribution of certain muscle groups, between bulls with secondary sexual characteristics (bulls(+)), those without (bulls(−)), and steers were investigated. Two carcass mass groups (250–300 and 301–350 kg) were compared. Five carcasses of either mass group were studied within each sex condition group. Bulls(+) had a higher meat percentage (P < 0·05) than bulls(−) or steers. They also had a lower bone percentage than steers (P < 0·05), but non-significant differences were found between bulls(+) and bulls(−) for bone percentage. Significant differences (P < 0·05) between sex condition groups were found for percentages of hindquarter, as well as for distribution of high-priced cuts. Steers had the most favourable distribution and bulls(+) the least favourable. Bulls(−) were intermediate.

Masculinity significantly (P < 0·05) influenced the distribution of the chuck, neck, brisket and hind shin cuts, whilst mass had a significant effect on the percentage hind shin and percentage thin flank. It was found that the M. rhomboideus was the only muscle of those studied that was significantly affected by masculinity and it was concluded that this muscle could be used as an indicator of the masculinity of the carcass.

The economic values of the carcasses of steers, bulls without secondary sexual development and bulls with secondary sexual development differed non-significantly.     

Spawning behaviour and early development of the Clanwilliam yellowfish (Barbus capensis; Cyprinidae), linked to experimental dam releases in the Olifants River,South Africa

This paper describes an investigation of how experimental releases of pulses of high flow from Clanwilliam Dam (Olifants River, South Africa) affect spawning of the Clanwilliam yellowfish, Barbus capensis. This species is endemic to the Olifants River system and is listed as rare in the Red Data Book of fishes for South Africa. Spawning sites are described, as is the spawning behaviour of B. capensis after specific experimental pulses released during the suspected spawning season of the species. Spawning and the developmental stages of embryos, free embryos, and larval B. capensis were studied using direct observations, video recordings, and microscopic examination of live embryos. B. capensis was found to be a repeat-spawner over several days as well as a multiple-spawner throughout the 4 month reproductive season. At present, spawning of B. capensis occurs down-stream of the dam sporadically (and possibly with limited recruitment), concurrent with releases of water for irrigation purposes. Experimental pulses appeared to trigger an increase in spawning activity, as an abundance of larvae was found down-stream 2 months later. It is suggested that a water-release strategy from Clanwilliam Dam could be designed to increase the number of B. capensis in the Olifants River. © 1997 John Wiley & Sons, Ltd.