A Philosophical Underpinning for ISD

If information systems development (ISD) is to be anything other than an ad-hoc discipline it must have a theory-like foundation. This paper interleaves philosophical discussion of ISD with practical suggestions. A philosophy with radically different presuppositions allows us to take a multi-aspectual view of I.S. that can address even tricky problems of multiple stakeholders and unintended and indirect impact

Simmelian ties, organizational justice, and knowledge sharing in virtual workgroups

Much IS research brings a priori theoretical constructs to its domain of study, and this can generate distorted outcomes. To avoid this danger, IS research should be \u27lifeworld-oriented\u27. Characteristics of the lifeworld are drawn from philosophy and applied to examples of IS research. Surprisingly, both positivist and critical research can be both theorizing and lifeworld-oriented, though in different ways. A proposal is then made for \u27lifeworld-oriented IS research\u27, which, by taking into account the lifeworlds of both researcher and researched, can make IS research richer and more relevant

Coping with Poorly Understood Domains: the Example of Internet Trust

The notion of trust, as required for secure operations over the Internet, is important for ascertaining the source of received messages. How can we measure the degree of trust in authenticating the source? Knowledge in the domain is not established, so knowledge engineering becomes knowledge generation rather than mere acquisition. Special techniques are required, and special features of KBS software become more important than in conventional domains. This paper generalizes from experience with Internet trust to discuss some techniques and software features that are important for poorly understood domains

ICT in the classroom: a study of diverse aspects (9)

ICT has become ubiquitous in the classroom. This paper seeks a way to reveal ‘Down-to-Earth’ (DTE) issues meaningful to those using ICT in the classroom. DTE issues are those that are directly meaningful to users, which affect the quality of ICT use, unfortunately, the literature tends, to focus on issues of interest to management, IT suppliers and policy makers rather than users. This research explores a way to reveal the diversity of Down-to-Earth issues, uncover hidden issues, and reveal values teachers hold. An empirical study was carried out of twenty teachers from three primary schools by open interview. The data collected was analysed using Dooyeweerd’s aspects based on his philosophy of everyday life. The study shows that literature is a poor guide to which issues are meaningful, and that theories would benefit from taking Down-to-Earth issues into account. It recommends the use of aspectual analysis in policy-making and ICT design

On-sky results for the integrated microlens ring tip-tilt sensor

We present the first on-sky results of the microlens ring tip-tilt sensor. This sensor uses a 3D printed microlens ring feeding six multimode fibers to sense misaligned light, allowing centroid reconstruction. A tip-tilt mirror allows the beam to be corrected, increasing the amount of light coupled into a centrally positioned single-mode (science) fiber. The sensor was tested with the iLocater acquisition camera at the Large Binocular Telescope in Tucson, Arizona, in November 2019. The limit on the maximum achieved rms reconstruction accuracy was found to be 0.19/D in both tip and tilt, of which approximately 50% of the power originates at frequencies below 10 Hz. We show the reconstruction accuracy is highly dependent on the estimated Strehl ratio and simulations support the assumption that residual adaptive optics aberrations are the main limit to the reconstruction accuracy. We conclude that this sensor is ideally suited to remove post-adaptive optics noncommon path tip-tilt residuals. We discuss the next steps for concept development, including optimization of the lens and the fiber, tuning of the correction algorithm, and selection of optimal science cases

First shark from the late Devonian (Frasnian) gogo formation, Western Australia sheds new light on the development of tessellated calcified cartilage

Background: Living gnathostomes (jawed vertebrates) comprise two divisions, Chondrichthyes (cartilaginous fishes, including euchondrichthyans with prismatic calcified cartilage, and extinct stem chondrichthyans) and Osteichthyes (bony fishes including tetrapods). Most of the early chondrichthyan (‘shark’) record is based upon isolated teeth, spines, and scales, with the oldest articulated sharks that exhibit major diagnostic characters of the group—prismatic calcified cartilage and pelvic claspers in males—being from the latest Devonian, c. 360 Mya. This paucity of information about early chondrichthyan anatomy is mainly due to their lack of endoskeletal bone and consequent low preservation potential. Methodology/Principal Findings: Here we present new data from the first well-preserved chondrichthyan fossil from the early Late Devonian (ca. 380–384 Mya) Gogo Formation Lägerstatte of Western Australia. The specimen is the first Devonian shark body fossil to be acid-prepared, revealing the endoskeletal elements as three-dimensional undistorted units: Meckel’s cartilages, nasal, ceratohyal, basibranchial and possible epibranchial cartilages, plus left and right scapulocoracoids, as well as teeth and scales. This unique specimen is assigned to Gogoselachus lynnbeazleyae n. gen. n. sp.Conclusions/Significance: The Meckel’s cartilages show a jaw articulation surface dominated by an expansive cotylus, and a small mandibular knob, an unusual condition for chondrichthyans. The scapulocoracoid of the new specimen shows evidence of two pectoral fin basal articulation facets, differing from the standard condition for early gnathostomes which have either one or three articulations. The tooth structure is intermediate between the ‘primitive’ ctenacanthiform and symmoriiform condition, and more derived forms with a euselachian-type base. Of special interest is the highly distinctive type of calcified cartilage forming the endoskeleton, comprising multiple layers of nonprismatic subpolygonal tesserae separated by a cellular matrix, interpreted as a transitional step toward the tessellated prismatic calcified cartilage that is recognized as the main diagnostic character of the chondrichthyans

Knowledge Issues Raised in Modelling Trust in a Public Key Infrastructure

The paper describes a knowledge based system (KBS) for modelling trust in the Certification Authority (CA) of a Public Key Infrastructure (PKI). It was built using a graphical KBS toolkit, Istar, that allows the knowledge builder to easily model the important relationships between concepts of the domain. The knowledge base was initially built using published work and was subsequently extended by knowledge obtained from leading PKI experts. The first prototype system computes the trust in a CA by asking the user a series of questions about the CA's Certification Practice Statement. Examples of its use with two well known public CAs is discussed. An important issue raised and discussed in this paper is how to map symbols in the KB to the knowledge level of human trust and beliefs, for such an ill-defined area of knowledge as trust, and four main mappings have been identified. Another issue that emerged relates to the use of questionnaires during knowledge acquisition. The expert system is currently available online via the Istar Knowledge Server, and future work is discussed