This paper is to design Dimensional Analysis (DA) algorithms for the multidimensional Lucid, the equational data flow language, which also includes user-defined functions. The significance is that the DA is indispensable for an efficient implementation of multidimensional Lucid and should aid the implementation of other data flow systems, such as Google’s TensorFlow. Data flow is a form of computation in which components of Multidimensional Data-sets (MDDs) travel on communication lines in a network of processing stations. Each processing station incrementally transforms its input MDDs to its output, another (possibly very different) MDD. MDDs are very common in Health Information Systems and data science in general. An important concept is that of a relevant dimension. A dimension is relevant if the coordinate of that dimension is required to extract a value. It is essential that in calculating with MDDs we avoid non-relevant dimensions, otherwise, we duplicate entries (say, in a cache) and waste time and space.For example, if X is the MDD of raw rain measurements, its dimensionality is {location, day, hour}, and that of Y is {location, day}. Note that the dimensionality is more than just the rank, which is simply the number of dimensions. Previously, there was extensive research on data-flow itself, which we summarize. Nevertheless, an exhaustive literature search uncovered no relevant previous DA work. Our methodology is that we proceeded incrementally, solving increasingly difficult instances of DA corresponding to increasingly sophisticated language features. However, in this paper, we solved the DA of multidimensional Data Flow (DF) programs. We also solved the difficult problem (which the GLU (Granular Lucid) team never solved) of determining the dimensionality of the DF programs that include user-defined functions, including recursively defined functions. We do this by adapting the PyLucid interpreter (to produce the DAM interpreter) to evaluate the entire program over the (finite) domain of dimensionalities. As a result, the experimentally validated algorithms in our paper can produce useful upper bounds for the dimensionalities of the variables in multidimensional PyLucid programs. That also includes those with user-defined functions.

Recent years have seen a boom in information technology, and the mobile mental healthcare system has also developed rapidly. However, it is necessary to understand users’ intention to use the system. Based on the Health Belief Model (HBM) and the Technology Acceptance Model (TAM), this study developed a usability evaluation model to assess users’ intention to use the system through experiments. It developed the Mobile Emotion Healthcare system based on machine learning and sentiment analysis techniques, which users can access with their smartphones to help them provide emotional care. The findings indicated that ‘health consciousness’, ‘perceived usefulness’, ‘perceived ease of use’ and ‘attitude’ all had a significant effect on users’ intention to use’ the Mobile Emotion Healthcare system.

Business Intelligence and the Kimball methodology, often referred to as dimensional modelling, are well established in data warehousing as a successful means of turning data into information. These techniques have been utilized in multiple business areas such as banking, manufacturing, marketing, sales, healthcare and more. Several articles have also shown how the Kimball approach can and has been used in the development of clinical research databases. However, these articles have also shown that there are weaknesses to the Kimball methodology when applied to complex areas such as clinical research. This paper describes our approach to address these weaknesses and meet the more sophisticated needs of health researchers by leveraging relationships within the underlying data and advanced techniques in the Kimball methodology.