Government and Social Media: A Case Study of 31 Informational World Cities

Social media platforms are increasingly being used by governments to foster user interaction. Particularly in cities with enhanced ICT infrastructures (i.e., Informational World Cities) and high internet penetration rates, social media platforms are valuable tools for reaching high numbers of citizens. This empirical investigation of 31 Informational World Cities will provide an overview of social media services used for governmental purposes, of their popularity among governments, and of their usage intensity in broadcasting information online.Comment: In Proceedings of the 47th Hawaii International Conference on System Sciences (pp. 1715-1724). IEEE Computer Society, 201

Orbital ordering promotes weakly-interacting S=1/2 dimers in the triangular lattice compound Sr3Cr2O8

The weakly interacting S=1/2 dimers system Sr3Cr2O8 has been investigated by powder neutron diffraction and inelastic neutron scattering. Our data reveal a structural phase transition below room temperature corresponding to an antiferro-orbital ordering with nearly 90 degrees arrangement of the occupied 3z^2-r^2 d-orbital. This configuration leads to a drastic reduction of the inter-dimer exchange energies with respect to the high temperature orbital-disorder state, as shown by a spin-dimer analysis of the super-superexchange interactions performed using the Extended Huckel Tight Binding method. Inelastic neutron scattering reveals the presence of a quasi non-dispersive magnetic excitation at 5.4 meV, in agreement with the picture of weakly-interacting dimers

A Comparison of The Content of Text Books In Geography In Relation To The Major Objectives To Be Obtained

The problem of this thesis is to determine how nearly certain selected textbooks of recent date in geography are adapted to attain objectives of geography found listed in published authoritative sources in the field of geography. The thesis is limited in its scope in that it uses only the second book of the series, in the texts thus in a measure getting the same level of material in each case

Validation of a Respiratory Gating System for Automated Delivery of the Deep Inspiration Breath-hold Technique

Purpose: To validate the performance of a respiratory gating system for the automated delivery of the deep inspiration breath-hold (DIBH) technique. Methods: The gating system utilized an automatic gating interface (Elekta Response) which connected a marker-based respiratory motion monitoring system to the linear accelerator control system. The gating system was characterized dosimetrically and temporally using two distinct approaches. Central-axis output and energy constancy were evaluated across 8 beam-matched linear accelerators. Additionally, a representative set of 5 treatment plans were delivered both non-gated and gated to a 2D diode array (MapCHECK). The respiratory motion monitoring system optically tracked a reflective marker that was attached to a dynamic phantom (QUASAR). The phantom was programmed to replicate a typical DIBH breathing waveform. The passing rates between these modes of operation were evaluated using gamma analysis and a percent dose difference comparison. Modular and end-to-end approaches were used to quantify system latencies. The modular components evaluated were the streaming latency of the tracking camera, sampling rate of the tracking software, signal travel time, and latency of the linear accelerator. The end-to-end approach involved measuring the displacement of a target moving at known velocities during the during the gating process. Results: Output and energy constancy were both within ± 0.5% for each beam energy and linear accelerator investigated. The average differences in passing rates between non-gated and gated modes of operation were within ± 0.4% using gamma analysis (2%, 1mm). Average passing rates between modes of operation were greater than 99% using a percent dose difference comparison (1%). The first gated segment was found to have significantly (p =.02) longer beam-on latency compared to the subsequent gated segment. End-to-end beam-on and beam-off latency for the subsequent gated segment was found to be 1.49 and 0.34 seconds, respectively, which was consistent with measured component totals. Conclusion: The gating system was able to achieve dosimetric operating characteristics that are desirable for accurate delivery of the DIBH technique. The methodology presented can be generalized to other respiratory gating systems that utilize the automatic gating interface studied in this work

PAHs and star formation in the HII regions of nearby galaxies M83 and M33

We present mid-infrared (MIR) spectra of HII regions within star-forming galaxies M83 and M33. Their emission features are compared with Galactic and extragalactic HII regions, HII-type galaxies, starburst galaxies, and Seyfert/LINER type galaxies. Our main results are as follows: (i) the M33 and M83 HII regions lie in between Seyfert/LINER galaxies and HII-type galaxies in the 7.7/11.3 - 6.2/11.3 plane, while the different sub-samples exhibiting different 7.7/6.2 ratios; (ii) Using the NASA Ames PAH IR Spectroscopic database, we demonstrate that the 6.2/7.7 ratio does not effectively track PAH size, but the 11.3/3.3 PAH ratio does; (iii) variations on the 17 $\mu$m PAH band depends on object type; however, there is no dependence on metallicity for both extragalactic HII regions and galaxies; (iv) the PAH/VSG intensity ratio decreases with the hardness of the radiation field and galactocentric radius (Rg), yet the ionization alone cannot account for the variation seen in all of our sources; (v) the relative strength of PAH features does not change significantly with increasing radiation hardness, as measured through the [NeIII]/[NeII] ratio and the ionization index; (vi) We present PAH SFR calibrations based on the tight correlation between the 6.2, 7.7, and 11.3 $\mu$m PAH luminosities with the 24 $\mu$m luminosity and the combination of the 24 $\mu$m and H$\alpha$ luminosity; (vii) Based on the total luminosity from PAH and FIR emission, we argue that extragalactic HII regions are more suitable templates in modeling and interpreting the large scale properties of galaxies compared to Galactic HII regions.Comment: 26 pages, 24 figures, 6 tables. Accepted for publication in MNRA

Herschel PACS and SPIRE spectroscopy of the Photodissociation Regions associated with S 106 and IRAS 23133+6050

Photodissociation regions (PDRs) contain a large fraction of all of the interstellar matter in galaxies. Classical examples include the boundaries between ionized regions and molecular clouds in regions of massive star formation, marking the point where all of the photons energetic enough to ionize hydrogen have been absorbed. In this paper we determine the physical properties of the PDRs associated with the star forming regions IRAS 23133+6050 and S 106 and present them in the context of other Galactic PDRs associated with massive star forming regions. We employ Herschel PACS and SPIRE spectroscopic observations to construct a full 55-650 {\mu}m spectrum of each object from which we measure the PDR cooling lines, other fine- structure lines, CO lines and the total far-infrared flux. These measurements are then compared to standard PDR models. Subsequently detailed numerical PDR models are compared to these predictions, yielding additional insights into the dominant thermal processes in the PDRs and their structures. We find that the PDRs of each object are very similar, and can be characterized by a two-phase PDR model with a very dense, highly UV irradiated phase (n $\sim$ 10^6 cm^(-3), G$_0$ $\sim$ 10^5) interspersed within a lower density, weaker radiation field phase (n $\sim$ 10^4 cm^(-3), G$_0$ $\sim$ 10^4). We employed two different numerical models to investigate the data, firstly we used RADEX models to fit the peak of the $^{12}$CO ladder, which in conjunction with the properties derived yielded a temperature of around 300 K. Subsequent numerical modeling with a full PDR model revealed that the dense phase has a filling factor of around 0.6 in both objects. The shape of the $^{12}$CO ladder was consistent with these components with heating dominated by grain photoelectric heating. An extra excitation component for the highest J lines (J > 20) is required for S 106.Comment: 20 pages, 10 figures, A&A Accepte

Arbeitsmarkt Informationswirtschaft (The labour market of the information sector)

"The information sector is understood as the entire branch of information system services and the corresponding company-internal function in business enterprises and authorities. There are no figures available on the volume of the information sector labour market. Experts' estimations were gathered both from western German managers in industrial enterprises (N = 2,016) and from German information system specialists (N = 352) as to the present and expected medium-term employment prospects of this 'occupation of the future'. According to the estimations of the industrial managers, on the whole graduates in information systems technology do not currently have good job prospects in German industry. In the medium-term, however, the employment prospects increase rapidly in the secondary sector. The present labour market situation is judged more positively by information system specialists employed in industry than it is by the managers interviewed. In the medium term the judgments are similar. Businesses in the service sector already have a high need for graduates in information systems technology. In the medium term the situation on the labour market for information systems graduates will improve by far according to the estimations of the information system specialists. An overproportionally high demand for graduates in information systems technology is signalised in the tertiary sector. Very small service enterprises (1-19 employees) have an extremely high demand for information systems graduates." (Author's abstract, IAB-Doku) ((en))Informationswirt, Informationsberufe, Berufsprobleme, Arbeitsmarktchancen, Informationswirtschaft, Wirtschaftszweige