Business goals, user needs, and requirements: A problem frame-based view

Background: It is well known that the analysis of requirements involves several stakeholders and perspectives. Very often several points of view at different abstraction levels have to be taken into account: all these features make requirements analysis a complex task. Such intrinsic complexity makes it difficult to understand several of the basic concepts that underlie requirements engineering. Actually, there is some confusion \u2013especially in industry\u2013 about what really a user requirement is, what are the differences between user requirements and user needs, and what are their relationships with business processes. Objective: The paper aims at clarifying the aforementioned issues, by providing a systematic and clear method for establishing requirements hierarchies. Method: The problem of describing requirements hierarchies is tackled using the problem frames concepts and notation. A case study is used throughout the paper to illustrate the proposed approach. Results: The description of requirements at different levels of abstractions and requirements hierarchies are illustrated. The resulting models are coherent with the reference model for requirements specifications and the problem frames. An analysis process that is aware of the differences between user needs and requirements is also provided, to illustrate the process of refining high-level goals into requirements that can be satisfied by a hardware/software machine. Conclusions: The proposed method appears promising to model, study and evaluate the relationships between business processes and the strategies for achieving business goals based on the usage of information technology

Cassirer’s Philosophy of Symbolic Forms: Between Reason and Relativism; a Critical Appraisal

This paper pursues the double task of (a) presenting Cassirer’s Philosophy of Symbolic Forms as a systematic critique of culture and (b) assessing this systematic approach with regards to the question of reason vs. relativism. First, it reconstructs the development of his theory to its mature presentation in his Philosophy of Symbolic Forms. Cassirer here presents a critique of culture as fulfilling Kant’s critical work by insisting on the plurality of reason as spirit, manifesting itself in symbolic forms. In the second part, the consequences of this approach will be drawn by considering the systematics Cassirer intended with this theory. As can be reconstructed from his metaphilosophical reflections, the strength of Cassirer’s philosophy is that it accounts for the plurality of rational-spiritual activity while at the same time not succumbing to a relativism. The Philosophy of Symbolic Forms steers a middle course between a rational fundamentalism and a postmodern relativism

The White Dwarf Distance to the Globular Cluster 47 Tucanae and its Age

We present a new determination of the distance (and age) of the Galactic globular cluster 47 Tucanae (NGC 104) based on the fit of its white dwarf (WD) cooling sequence with the empirical fiducial sequence of local WD with known trigonometric parallax, following the method described in Renzini et al. (1996). Both the cluster and the local WDs were imaged with HST+WFPC2 using the same instrument setup. We obtained an apparent distance modulus of $(m-M)_V=13.27\pm0.14$ consistent with previous ground-based determinations and shorter than that found using HIPPARCOS subdwarfs. Coupling our distance determination with a new measure of the apparent magnitude of the main sequence turnoff, based on our HST data, we derive an age of $13\pm2.5$ Gyr.Comment: Accepted for publication on the Astrophysical Journa

The Distance to NGC 5904 (M 5) via the Subdwarfs Main Sequence Fitting Method

We present a determination of the distance modulus of the globular cluster NGC 5904 (M 5), obtained by means of the subdwarf main-sequence fitting on the (V,V-I) color-magnitude diagram. The subdwarf sample has been selected from the HIPPARCOS catalog in a metallicity range homogeneous with the cluster ([Fe/H] \~= -1.1). Both the cluster and the subdwarfs have been observed with the same telescope+instrument+filters setup (namely, ESO-NTT equipped with the SUSI2 camera), in order to preserve homogeneity and reduce systematic uncertainties. A set of archival HST data has then been used to obtain a deep and precise ridge line. These have been accurately calibrated in the ground photometric system by using the NTT data and used to fit the cluster distance modulus. By adopting the most commonly accepted values for the reddening, E(B-V) = 0.035 and 0.03, we obtain respectively mu_0 = 14.44 +- 0.09 +- 0.07 and mu_0 = 14.41 +- 0.09 +- 0.07, in agreement with recent determinations.Comment: 11 pages, 14 figures, accepted for publication in Astronomy and Astrophysic

Wireless Software Synchronization of Multiple Distributed Cameras

We present a method for precisely time-synchronizing the capture of image sequences from a collection of smartphone cameras connected over WiFi. Our method is entirely software-based, has only modest hardware requirements, and achieves an accuracy of less than 250 microseconds on unmodified commodity hardware. It does not use image content and synchronizes cameras prior to capture. The algorithm operates in two stages. In the first stage, we designate one device as the leader and synchronize each client device's clock to it by estimating network delay. Once clocks are synchronized, the second stage initiates continuous image streaming, estimates the relative phase of image timestamps between each client and the leader, and shifts the streams into alignment. We quantitatively validate our results on a multi-camera rig imaging a high-precision LED array and qualitatively demonstrate significant improvements to multi-view stereo depth estimation and stitching of dynamic scenes. We release as open source 'libsoftwaresync', an Android implementation of our system, to inspire new types of collective capture applications.Comment: Main: 9 pages, 10 figures. Supplemental: 3 pages, 5 figure