Layout to circuit extraction for three-dimensional thermal-electrical circuit simulation of device structures

In this paper, a method is proposed for extraction of coupled networks from layout information for simulation of electrothermal device behavior. The networks represent a three-dimensional (3-D) device structure with circuit elements. The electrical and thermal characteristics of this circuit representation are calculated with a circuit simulator. Spatial potential distributions, current flows, and temperature distributions in the device structure are calculated on the spatial coordinates. This simulation method can be placed between device simulation and (conventional) circuit simulation. It has been implemented in a circuit simulator and is demonstrated for simulation of self-heating in a bipolar low frequency power transistor. The main advantage of this simulation method is that not only the 3-D thermal behavior of the whole chip is simulated, but that this is also directly coupled to the electrical device behavior by means of the power dissipation and temperature distribution in the device. This offers the possibility for the circuit designer to simulate 3-D, coupled, thermal-electrical problems with a circuit simulator. As an example, the influence of the emitter contacting on the internal temperature and current distribution of a BJT is investigate

Geomorphological mapping and geophysical profiling for the evaluation of natural hazards in an alpine catchment

International audienceLiechtenstein has faced an increasing number of natural hazards over recent decades: debris flows, slides, snow avalanches and floods repeatedly endanger the local infrastructure. Geomorphological field mapping and geo-electrical profiling was used to assess hazards near Malbun, a village potentially endangered by landslides, and especially debris flows. The area is located on the tectonic contacts of four different nappe slices. The bedrock consists of anhydrite and gypsum, dolomite, shale, marl, and limestone. The spatial distribution and occurrence of debris flows and slides is evaluated through a combination of geomorphological expert knowledge, and detailed visualization in a geographical information system. In a geo-database a symbol-based 1:3000 scale geomorphological map has been digitized and rectified into polygons. The polygons include information on the main geomorphological environment, the Quaternary material distribution and of geomorphological processes, which are stored in attribute tables. The spatial distribution of these attributes is then combined with geophysical information and displacement rates interpolated from benchmark measurements. On one of the landslides two geo-electrical profiles show that the distance to a potential failure plane varies between 10-20 m and that the topography of the failure plane is influenced by subterranean gypsum karst features. The displacement measurements show that this landslide actively disintegrates into minor slides and is not, therefore, a risk to the village of Malbun. The hazard zonation indicates that debris flows can pose a risk if no countermeasures are taken. Gypsum karst may locally accelerate the landslide activity. In contrast, the impact of debris flows is diminished because collapse dolines may act as sediment traps for the debris flow materials. This research illustrates how geomorphological expert knowledge can be integrated in a GIS for the evaluation of natural hazards on a detailed scale

Automated semantic trajectory annotation with indoor point-of-interest visits in urban areas

User trajectories contain a wealth of implicit information. The places that people visit, provide us with information about their preferences and needs. Furthermore, it provides us with information about the popularity of places, for example at which time of the year or day these places are frequently visited. The potential for behavioral analysis of trajectories is widely discussed in literature, but all of these methods need a pre-processing step: the geometric trajectory data needs to be transformed into a semantic collection or sequence of visited points-of-interest that is more suitable for data mining. Especially indoor activities in urban areas are challenging to detect from raw trajectory data. In this paper, we propose a new algorithm for the automated detection of visited points-of-interest. This algorithm extracts the actual visited points-of-interest well, both in terms of precision and recall, even for the challenging urban indoor activity detection. We demonstrate the strength of the algorithm by comparing it to three existing and widely used algorithms, using annotated trajectory data, collected through an experiment with students in the city of Hengelo, The Netherlands. Our algorithm, which combines multiple trajectory pre-processing techniques from existing work with several novel ones, shows significant improvements

Spatiotemporal behavior profiling: a treasure hunt case study

Trajectories have been providing us with a wealth of derived information such as traffic conditions and road network updates. This work focuses on deriving user profiles through spatiotemporal analysis of trajectory data to provide insight into the quality of information provided by users. \ud The presented behavior profiling method assesses user participation characteristics in a treasure-hunt type event. Consisting of an analysis and a profiling phase, analysis involves a timeline and a stay-point analysis, as well as a semantic trajectory inspection relating actual and expected paths. The analysis results are then grouped around profiles that can be used to estimate the user performance in the activity.\ud \ud The proposed profiling method is evaluated by means of a student orientation treasure-hunt activity at the University of Twente, The Netherlands. The profiling method is used to predict the students' gaming behavior by means of a simple team type classification, and a feature-based answer type classification

Generic knowledge-based analysis of social media for recommendations

Recommender systems have been around for decades to help people find the best matching item in a pre-defined item set. Knowledge-based recommender systems are used to match users based on information that links the two, but they often focus on a single, specific application, such as movies to watch or music to listen to. In this presentation, we present our Interest-Based Recommender System (IBRS). This knowledge-based recommender system provides recommendations that are generic in three dimensions: IBRS is (1) domain-independent, (2) language-independent, and (3) independent of the used social medium. To match user interests with items, the first are derived from the user's social media profile, enriched with a deeper semantic embedding obtained from the generic knowledge base DBpedia. These interests are used to extract personalized recommendations from a tagged item set from any domain, in any language. We also present the results of a validation of IBRS by a test user group of 44 people using two item sets from separate domains: greeting cards and holiday homes

Higher return to pre-injury type of sports after revision anterior ligament reconstruction with lateral extra-articular tenodesis compared to without lateral extra-articular tenodesis

PurposeTo evaluate the rate of return to pre-injury type of sports (RTS type) in patients after revision anterior cruciate ligament reconstruction (ACLR) with lateral extra-articular tenodesis (LET) compared to patients after revision ACLR without LET.MethodsSeventy-eight patients who underwent revision ACLR with an autologous ipsilateral bone-patellar tendon-bone autograft with and without LET were included at least one year after surgery (mean follow-up: 43.9, SD: 29.2 months). All patients filled in a questionnaire about RTS type, the Knee injury and Osteoarthritis Outcome Score (KOOS), the International Knee Documentation Committee subjective form (IKDCsubjective), and the Tegner activity score.ResultsThe RTS type for revision ACLR with LET was 22 of 42 (52%), whereas 11 of 36 (31%) of the patients who underwent revision ACLR without LET returned to the pre-injury type of sport (p = 0.05). No significant differences were found in KOOS subscores, IKDCsubjective, and Tegner activity scores.ConclusionAn additional LET increases the rate of RTS type after revision ACLR

Probing the missing baryons with the Sunyaev-Zel'dovich effect from filaments

Observations of galaxies and galaxy clusters in the local universe can account for only $\sim\,10\%$ of the total baryon content. Cosmological simulations predict that the `missing baryons' are spread throughout filamentary structures in the cosmic web, forming a low-density gas with temperatures of $10^5-10^7\,\!$K. We search for this warm-hot intergalactic medium (WHIM) by stacking the Planck Compton $y$-parameter map of the thermal Sunyaev-Zel'dovich (tSZ) effect for 1,002,334 pairs of CMASS galaxies from the Sloan Digital Sky Survey. We model the contribution from the galaxy halo pairs assuming spherical symmetry, finding a residual tSZ signal at the 2.9\mbox{\sigma} level from a stacked filament of length $10.5\,h^{-1}\,\rm Mpc$ with a Compton parameter magnitude $y=(0.6\pm0.2)\times10^{-8}$. We consider possible sources of contamination and conclude that bound gas in haloes may contribute only up to $20\%$ of the measured filamentary signal. To estimate the filament gas properties we measure the gravitational lensing signal for the same sample of galaxy pairs; in combination with the tSZ signal, this yields an inferred gas density of $\rho_{\rm b}=(5.5\pm 2.9)\times\bar{\rho_{\rm b}}$ with a temperature $T=(2.7\pm 1.7) \times 10^6\,$K. This result is consistent with the predicted WHIM properties, and overall the filamentary gas can account for $11\pm 7\%$ of the total baryon content of the Universe. We also see evidence that the gas filament extends beyond the galaxy pair. Averaging over this longer baseline boosts the significance of the tSZ signal and increases the associated baryon content to $28\pm 12\%$ of the global value.Comment: 13 pages, 8 figures; accepted for publication in A&

Barriers to home care for terminally ill Turkish and Moroccan migrants, perceived by GPs and nurses: a survey

BACKGROUND: Previous qualitative research proved that relatives of elderly terminally ill Turkish and Moroccan immigrants experience several barriers to the use of Dutch professional home care. The aim of this study was to explore how general practitioners and home care nurses perceive the home care for terminally ill Turkish and Moroccan migrants and their families in the Netherlands. METHODS: Questionnaires were sent to home care organizations and GPs working in areas where most of these migrants are living. 93 nurses and 78 GPs provided information about their experiences and opinions regarding home care for this group of patients. The data were analyzed by descriptive statistics. RESULTS: GPs refer relatively few patients from these migrant groups to home care. They often find it difficult to assess the needs of these patients and their families. In 40% of the GPs' cases in which terminally ill Turkish and Moroccan migrants were not referred to home care, the GP regretted this afterwards: the patients had not received sufficient qualified care, and their informal carers had often become overburdened. In addition, home care nurses often express dissatisfaction with the home care given to terminally ill Turkish or Moroccan patients, because of communication problems, the patients' lack of knowledge of the disease, or difficulties in making suitable appointments with the patient or with the family. CONCLUSIONS: Nurses and GPs cite chiefly similar factors influencing access to and use of home care as family members did in a previous study. However, according to GPs and nurses, the main barrier to the use of home care concerns communication problems, while relatives cited the preference for family care as the main reason for abstaining from the use of home care. (aut. ref.