8,531 research outputs found

    Searching for Standards: Disclosure in the Municipal Securities Market

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    Prokrastinering, eller att mot bÀttre vetande skjuta upp nÄgot, Àr ett stort problem i samhÀllet i allmÀnhet och för studenter i synnerhet. I denna artikel beskriver vi en utbildningsmodul om prokrastinering som vi introducerat pÄ tvÄ civilingenjörsprogram pÄ KTH, varav denna rapport behandlar datateknikprogrammet dÀr 466 studenter deltog. UtvÀrderingen hade 100% svarsfrekvens, och visar att 95% av studenterna hade problem med prokrastinering varav 43% hade stora eller mycket stora problem. 88% ansÄg att prokrastinering var ett bra tema att ha med i utbildningen, och 57% ansÄg att momentet haft positiva effekter pÄ deras studievanor. Endast 7% ansÄg att momentet inte hade gett nÄgra mÀrkbara effekter pÄ studierna. DÄ modulen endast krÀver ca 8 timmars arbete frÄn studenternas sida anser vi att fördelarna Àr sÄ stora att denna eller en liknande modul borde ingÄ i samtliga utbildningsprogram.QC 20131216</p

    Stability Criteria for Breached Pair Superfluidity

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    We present simple, concrete, two-fermion models that exhibit thermodynamically stable isotropic translationally-invariant gapless superfluid states (breached pair superfluidity). The mass ratio between the components and the momentum structure of the interaction are crucial for determining the stability of such states: Idealized, momentum-independent (``contact'') interactions are insufficient.Comment: 5 pages, REVTeX4. Minor updates in response to comments. References adde

    Forensic Schedule Analysis of Construction Delay in Military Projects in the Middle East

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    This research performs forensic schedule analysis of delay factors that impacted recent large-scale military construction projects in the Middle East. The purpose of this study is to understand the most significant causes of project delay and how AFCEC might improve schedule management performance. The methodologies for analysis are adapted from the Professional Practice Guide to Forensic Schedule Analysis, particularly Method 3.7 Modeled/Additive/Multiple Base, or Time Impacted Analysis—Adjusted. The data is gathered from USACE and AFCEC, consisting of Primavera project schedules and project documents from the Resident Management System database. The project delays from two large-scale projects are apportioned as compensable, excusable, or non-excusable based on their liability and their impacts to the critical path. This investigation reveals that two particular delay factors are the most significant contributors to schedule overrun, accounting for 62% of the total delay. Obtaining building permits, an owner (government) responsibility, contributed to 38% of the delays. Design issues, consisting of change orders and submittal approvals, accounted for another 24% of the delays. In order to reduce schedule delay in future projects, several recommendations are provided that focus on various aspects of project management

    Diamonds on the Hat: Globular Clusters in The Sombrero Galaxy (M104)

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    Images from the HST ACS are used to carry out a new photometric study of the globular clusters (GCs) in M104, the Sombrero galaxy. The primary focus of our study is the characteristic distribution function of linear sizes (SDF) of the GCs. We measure the effective radii for 652 clusters with PSF-convolved King and Wilson dynamical model fits. The SDF is remarkably similar to those measured for other large galaxies of all types, adding strong support to the view that it is a "universal" feature of globular cluster systems. We develop a more general interpretation of the size distribution function for globular clusters, proposing that the shape of the SDF that we see today for GCs is strongly influenced by the early rapid mass loss during their star forming stage, coupled with stochastic differences from cluster to cluster in the star formation efficiency (SFE) and their initial sizes. We find that the observed SDF shape can be accurately predicted by a simple model in which the protocluster clouds had characteristic sizes of 0.9±0.10.9 \pm 0.1 pc and SFEs of 0.3±0.070.3 \pm 0.07. The colors and luminosities of the M104 clusters show the clearly defined classic bimodal form. The blue sequence exhibits a mass/metallicity relation (MMR), following a scaling of heavy-element abundance with luminosity of Z∌L0.3Z \sim L^{0.3} very similar to what has been found in most giant elliptical galaxies. A quantitative self-enrichment model provides a good first-order match to the data for the same initial SFE and protocluster size that were required to explain the SDF. We also discuss various forms of the globular cluster Fundamental Plane (FP) of structural parameters, and show that useful tests of it can be extended to galaxies beyond the Local Group.Comment: In press for MNRA

    Dust and ionized gas in active radio elliptical galaxies

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    The authors present broad and narrow bandwidth imaging of three southern elliptical galaxies which have flat-spectrum active radio cores (NGC 1052, IC 1459 and NGC 6958). All three contain dust and extended low excitation optical line emission, particularly extensive in the case of NGC 1052 which has a large H alpha + (NII) luminosity. Both NGC 1052 and IC 1459 have a spiral morphology in emission-line images. All three display independent strong evidence that a merger or infall event has recently occurred, i.e., extensive and infalling HI gas in NGC 1052, a counter-rotating core in IC 1459 and Malin-Carter shells in NGC 6958. This infall event is the most likely origin for the emission-line gas and dust, and the authors are currently investigating possible excitation mechanisms (Sparks et al. 1990)

    Orbital maneuvering end effectors

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    This invention relates to an end effector device for grasping and maneuvering objects such as berthing handles of a space telescope. The device includes a V-shaped capture window defined as inclined surfaces in parallel face plates which converge toward a retainer recess in which the handle is retained. A pivotal finger (30) meshes with a pair of pivoted fingers which rotate in counterrotation. The fingers rotate to pull a handle within the capture window into recess where latches lock handle in the recess. To align the capture window, plates may be cocked plus or minus five degrees on base. Drive means is included in the form of a motor coupled with a harmonic drive speed reducer, which provides for slow movement of the fingers at a high torque so that large articles may be handled. Novelty of the invention is believed to reside in the combined intermeshing finger structure, drive means and the harmonic drive speed reducer, which features provide the required maneuverability and strength
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