Use and non‐use of VDTs—organization of terminal work: Research findings from Swedish cross‐site studies in the field of office automation

A group of users in Copenhagen were asked to evaluate how important a number of user interface characteristics were for them. The results show high importance of efficient daily use and of possibilities for exploratory learning while tutorial materials were of less importance. Users also were asked to evaluate four usability aspects of a number of popular programs. Results show that the quality pleasant to work with has the largest impact on evaluations of overall user‐friendliness while users seem able to view usability independently from the number of features in an application.     

Wetland change mapping for the U.S. mid-Atlantic region using an outlier detection technique

Although the impacts of wetland loss are often felt at regional scales, effective planning and management require a comparative assessment of local needs, costs, and benefits. Satellite remote sensing can provide spatially explicit, synoptic land cover change information to support such an assessment. However, a common challenge in conventional remote sensing change detection is the difficulty of obtaining phenologically and radiometrically comparable data from the start and end of the time period of interest. An alternative approach is to use a prior land cover classification as a surrogate for historic satellite data and to examine the self-consistency of class spectral reflectances in recent imagery. We produced a 30-meter resolution wetland change probability map for the U.S. mid-Atlantic region by applying an outlier detection technique to a base classification provided by the National Wetlands Inventory (NWI). Outlier-resistant measures – the median and median absolute deviation – were used to represent spectral reflectance characteristics of wetland class populations, and formed the basis for the calculation of a pixel change likelihood index. The individual scene index values were merged into a consistent region-wide map and converted to pixel change probability using a logistic regression calibrated through interpretation of historic and recent aerial photography. The accuracy of a regional change/no-change map produced from the change probabilities was estimated at 89.6%, with a Kappa of 0.779. The change probabilities identify areas for closer inspection of change cause, impact, and mitigation potential. With additional work to resolve confusion resulting from natural spatial heterogeneity and variations in land use, automated updating of NWI maps and estimates of areal rates of wetland change may be possible. We also discuss extensions of the technique to address specific applications such as monitoring marsh degradation due to sea level rise and mapping of invasive species.     

The use of social media in impact assessment: experiences among national infrastructure developers in Denmark

Social media plays an increasingly prominent role in the interaction between impact assessments and society. Impact assessment is thus becoming part of social networks that are claimed to be able to improve interaction between actors in impact assessment processes. By investigating the use of social media in impact assessment and planning processes of national linear infrastructure development, we explore how social media impinge on participatory practices and how the potential of social media is realized in the current use related to public participation processes. The study focuses on experiences among national developers working in road, rail, electricity, gas, and metro infrastructures in Denmark. The article shows that the current use of social media in public participatory practices is limited to branding and on-way communication and that the increasing use of social media in linear infrastructure planning gives rise to a variety of concerns among developers that are related to especially organizational cultures, perception of the target groups, and prioritization of resources.     

Intradermal and subcutaneous leiomyosarcoma: a clinicopathological and immunohistochemical study of 41 cases

Superficial leiomyosarcomas are rare tumours. The lesions confined to the dermis, contrary to those involving the subcutis, have been reported to carry a favourable prognosis. A retrospective study of 41 consecutive cases of surgically treated intradermal and subcutaneous leiomyosarcomas was undertaken in order to determine the prognostic factors that may influence the survival of these patients. Seven tumours were predominantly intradermal and 34 involved the subcutaneous tissue. Fifty-four percent of the tumours were located in the lower extremities. All cases stained positively for smooth muscle antigen and 66% for desmin. The tumours were classified with regard to tumour grade I (low grade, 3%), II (intermediate, 12%), IIIA (high grade, 46%) and IIIB (high grade, 39%). In all patients, follow-up information was available. Mean follow-up time was 5 years. The patients with intradermal tumours were all alive without signs of recurrence, whereas 14 of those with leiomyosarcomas involving the subcutis have died with pulmonary metastases. Our study confirms that "pure" intradermal leiomyosarcomas independent of tumour grade behave in a benign fashion, probably due to small tumour size. Tumour size > or = 5 cm, deep localization with fascia involvement, and high malignancy grade (IIIB) were found to deteriorate survival based on a univariate analysis. However, in a multivariate analysis only tumour size was found to be an independent prognostic factor.     

Improved Variational Guiding of Smoke Animations

Smoke animations are hard to art‐direct because simple changes in parameters such as simulation resolution often lead to unpredictable changes in the final result. Previous work has addressed this problem with a guiding approach which couples low‐resolution simulations – that exhibit the desired flow and behaviour – to the final, high‐resolution simulation. This is done in such a way that the desired low frequency features are to some extent preserved in the high‐resolution simulation. However, the steady (i.e. constant) guiding used often leads to a lack of sufficiently high detail, and employing time‐dependent guiding is expensive because the matrix of the resulting set of equations needs to be recomputed at every iteration. We propose an improved mathematical model for Eulerian‐based simulations which is better suited for dynamic, time‐dependent guiding of smoke animations through a novel variational coupling of the low‐ and high‐resolution simulations. Our model results in a matrix that does not require re‐computation when the guiding changes over time, and hence we can employ time‐dependent guiding more efficiently both in terms of storage and computational requirements. We demonstrate that time‐dependent guiding allows for more high frequency detail to develop without losing correspondence to the low resolution simulation. Furthermore, we explore various artistic effects made possible by time‐dependent guiding.     

A generalization of Paillier’s public-key system with applications to electronic voting

We propose a generalization of Paillier’s probabilistic public-key system, in which the expansion factor is reduced and which allows to adjust the block length of the scheme even after the public key has been fixed, without losing the homomorphic property. We show that the generalization is as secure as Paillier’s original system and propose several ways to optimize implementations of both the generalized and the original scheme. We construct a threshold variant of the generalized scheme as well as zero-knowledge protocols to show that a given ciphertext encrypts one of a set of given plaintexts, and protocols to verify multiplicative relations on plaintexts. We then show how these building blocks can be used for applying the scheme to efficient electronic voting. This reduces dramatically the work needed to compute the final result of an election, compared to the previously best known schemes. We show how the basic scheme for a yes/no vote can be easily adapted to casting a vote for up to t out of L candidates. The same basic building blocks can also be adapted to provide receipt-free elections, under appropriate physical assumptions. The scheme for 1 out of L elections can be optimized such that for a certain range of the other parameter values, the ballot size is logarithmic in L.     

Definition of the Linear Region of X-Ray -Induced Cable Response

Cable response to X-rays is linear with incident fluence, provided the deposited charge in cable dielectrics is directly proportional to the X-ray flux. To estimate the level at which the linear region ends, we discuss three nonlinear processes that modify the deposited charge profile in a hypothetical cable model: field-limiting in vacuum gaps, ionization effects in air-filled gaps, and radiation-induced dielectric conductivity. The exact level at which limiting of the Norton driver in an elemental length of cable begins depends on the cable geometry and the X-ray source. Estimates of the onset of nonlinearities caused by field-limiting and by dielectric conductivity are found in terms of cable and source parameters. With air-filled gaps, the Norton driver is always nonlinear. In addition to limiting of the Norton drivers, the load response of a long cable may be limited because propagating currents are attenuated by the induced conductivity of the bulk of the dielectric.     

Strategic piggybacking--a self-subsidization strategy for nonprofit institutions

Nonprofit institutions often find that their socially worthwhile primary missions generate deficits. The author proposes a strategy for funding these shortfalls that is a synthesis of the specialization and diversified portfolio strategies. Following the method of strategic piggybacking, an organization should acquire or develop a business that is new for the institution and that may be unrelated to the institution's primary mission. The purpose of this new activity is to subsidize, at least in part, the deficit-producing primary mission.     

In-network performance of handheld mobile terminals

This paper considers a realistic evaluation of the power mobile handsets are able to transmit and receive. It has been suggested to use the so-called total radiated power (TRP) and the total isotropic sensitivity (TIS) for the uplink and downlink, respectively, which may be seen as special cases of the general mean-effective-gain (MEG) measure. These measures are computed from the spherical radiation pattern of the handset and the different measures are obtained by using different models of the mobile propagation environment. In this paper, the results obtained via the spherical radiation patterns are compared with the equivalent performance obtained in a live Global System for Mobile Communications (GSM) network using data from the Abis network interface. This method does not require altering of the handsets and the testing uses normal calls in the network. The investigation is based on measurements with four different commercially available handsets carried out in two different indoor environments and involving 22 test users. In addition, a series of measurements were also made with a phantom simulating the handset user, allowing a test of how well the phantom represents the average user.