The value of information in information analysis

Information Requirements Analysis deals with defining the information needed for managerial purposes. It is considered as the first step of analysis in the development of an information system. This paper ties information requirements analysis with information evaluation. It is asserted that it is insufficient to simply find “needed” information items but also that such items should be evaluated in terms of their benefit.Three approaches to information evaluation are considered — realistic, normative and subjective. It is asserted that the normative approach may sometimes be applied in lower organizational levels, while at higher levels subjective evaluation is used. Some examples are discussed in this context. Finally, we discuss some procedures for applying evaluation in information analysis.     

Temperature dependence of the bandwidth of buried heterostructuredistributed feedback lasers

Reports that the etched-mesa buried-heterostructure distributed-feedback lasers (λ = 1.3 μm) fabricated using semi-insulating InP blocking lasers have bandwidths in the 12-17 GHz range at 20°C. 15 mW (18 GHz at 20 mW). The bandwidth decreases with increasing temperature at low powers. For the practical range of interest from 20°C to 40°C, the observed decrease in bandwidth is 1.0±0.5 GHz at 15 mW output power. A large sublinearity in the light-versus-current characteristics is generally associated with a rollover in the bandwidth power curve     

Mutual Influence Between Adhesion and Molecular Conformation: Molecular Geometry is a Key Issue in Interphase Formation

The influence of adhesion on molecular conformations—besides solely molecule orientation—and vice versa was rarely considered in adhesion science due to the difficult analysis of conformational equilibria, in general, and the high number of possible conformations in classical polymers, in particular. Fortunately, some insight is available from the interphase chemistry of proteins due to the importance regarding their biological function in heterogeneous systems. Peptides and proteins are, thus, ideal model systems for the experimental and theoretical investigation of conformational changes in interphases. The conformational equilibrium of any kind of compound or, more specifically, a polymer interacting with a surface must differ in the interphase when compared with the bulk. This is also the case for common adhesives. Therefore, we define that the interphase of an adhesive bond is the area in which the chemical composition or the conformational equilibrium differs from that of the bulk phase.     

Systems implementation languages and IRONMAN

The U.S. Department of Defense has recently issued a set of requirements, which it called IRONMAN, for the design of a programming language that it will use for embedded computer applications. To date four competing languages have been designed and, after considerable debate and scrutiny, these have been reduced to two. It is expected that the winning language will be selected during 1979. This report compares the IRONMAN requirements against the state-of-the-art in systems implementation language design in an attempt to see the extent to which IRONMAN can be met from existing technology. Particular emphasis is given to the areas of large-scale program structuring, parallel programming, exception handling and hardware interaction. Finally, Dijkstra's criticism of IRONMAN and the competing languages will be examined. It will be argued that he may be justified in doubting the viability of a language with such diverse features.     

Self contained high pressure cell, apparatus and procedure for the preparation of encapsulated proteins dissolved in low viscosity fluids for NMR spectroscopy

The design of a sample cell for high performance nuclear magnetic resonance (NMR) at elevated pressure is described. The cell has been optimized for the study of encapsulated proteins dissolved in low viscosity fluids but is suitable for more general NMR spectroscopy of biomolecules at elevated pressure. The NMR cell is comprised of an alumina toughened zirconia tube mounted on a self-sealing non-magnetic metallic valve. The cell has several advantages including relatively low cost, excellent NMR performance, high pressure tolerance, chemical inertness and a relatively large active volume. Also described is a low volume sample preparation device which allows for the preparation of samples under high hydrostatic pressure and their subsequent transfer to the NMR cell.     

A framework for empirical evaluation of conceptual modeling techniques

The paper presents a framework for the empirical evaluation of conceptual modeling techniques used in requirements engineering. The framework is based on the notion that modeling techniques should be compared via their underlying grammars. The framework identifies two types of dimensions in empirical comparisons—affecting and affected dimensions. The affecting dimensions provide guidance for task definition, independent variables and controls, while the affected dimensions define the possible mediating variables and dependent variables. In particular, the framework addresses the dependence between the modeling task—model creation and model interpretation—and the performance measures of the modeling grammar. The utility of the framework is demonstrated by using it to categorize existing work on evaluating modeling techniques. The paper also discusses theoretical foundations that can guide hypothesis generation and measurement of variables. Finally, the paper addresses possible levels for categorical variables and ways to measure interval variables, especially the grammar performance measures.     

Building Construction Sets by Tiling Grammar Simplification

This paper poses the problem of fabricating physical construction sets from example geometry: A construction set provides a small number of different types of building blocks from which the example model as well as many similar variants can be reassembled. This process is formalized by tiling grammars. Our core contribution is an approach for simplifying tiling grammars such that we obtain physically manufacturable building blocks of controllable granularity while retaining variability, i.e., the ability to construct many different, related shapes. Simplification is performed by sequences of two types of elementary Operations: non‐local joint edge collapses in the tile graphs reduce the granularity of the decomposition and approximate replacement Operations reduce redundancy. We evaluate our method on abstract graph grammars in addition to computing several physical construction sets, which are manufactured using a commodity 3D printer.     

Modelling Off-the-Shelf Information Systems Requirements: An Ontological Approach

Requirements for choosing off-the-shelf information systems (OISR) differ from requirements for development of new information systems in that they do not necessarily provide complete specifications, thus allowing flexibility in matching an existing IS to the stated needs. We present a framework for OISR conceptual models that consists of four essential elements: business processes, business rules, information objects and required system services. We formalise the definitions of these concepts based on an ontological model. The ontology-based OISR model provides a framework to evaluate modelling languages on how appropriate they are for OISR requirements specifications. The evaluation framework is applied to the Object-Process Methodology, and its results are compared with a similar evaluation of ARIS. This comparison demonstrates the effectiveness of the ontological framework for evaluating modelling tools on how well they can guide selection, implementation and integration of purchased software packages.     

Real‐Time Symmetry‐Preserving Deformation

In this paper, we address the problem of structure‐aware shape deformation: We specifically consider deformations that preserve symmetries of the shape being edited. While this is an elegant approach for obtaining plausible shape variations from minimal assumptions, a straightforward optimization is numerically expensive and poorly conditioned. Our paper introduces an explicit construction of bases of linear spaces of shape deformations that exactly preserve symmetries for any user‐defined level of detail. This permits the construction of low‐dimensional spaces of low‐frequency deformations that preserve the symmetries. We obtain substantial speed‐ups over alternative approaches for symmetry‐preserving shape editing due to (i) the sub‐space approach, which permits low‐res editing, (ii) the removal of redundant, symmetric information, and (iii) the simplification of the numerical formulation due to hard‐coded symmetry preservation. We demonstrate the utility in practice by applying our framework to symmetry‐preserving co‐rotated iterative Laplace surface editing of models with complex symmetry structure, including partial and nested symmetry.