Epistemic Logic with Partial Dependency Operator

In this paper, we introduce $\textit{partial}$ dependency modality $\mathcal{D}$ into epistemic logic so as to reason about $\textit{partial}$ dependency relationship in Kripke models. The resulted dependence epistemic logic possesses decent expressivity and beautiful properties. Several interesting examples are provided, which highlight this logic's practical usage. The logic's bisimulation is then discussed, and we give a sound and strongly complete axiomatization for a sub-language of the logic

Knowing Values and Public Inspection

We present a basic dynamic epistemic logic of "knowing the value". Analogous to public announcement in standard DEL, we study "public inspection", a new dynamic operator which updates the agents' knowledge about the values of constants. We provide a sound and strongly complete axiomatization for the single and multi-agent case, making use of the well-known Armstrong axioms for dependencies in databases

Spin dependent electron transport through a magnetic resonant tunneling diode

Electron transport properties in nanostructures can be modeled, for example, by using the semiclassical Wigner formalism or the quantum mechanical Green's functions formalism. We compare the performance and the results of these methods in the case of magnetic resonant-tunneling diodes. We have implemented the two methods within the self-consistent spin-density-functional theory. Our numerical implementation of the Wigner formalism is based on the finite-difference scheme whereas for the Green's function formalism the finite-element method is used. As a specific application, we consider the device studied by Slobodskyy et all. [Phys. Rev. Lett. 90, 246601 (2003)] and analyze their experimental results. The Wigner and Green's functions formalisms give similar electron densities and potentials but, surprisingly, the former method requires much more computer resources in order to obtain numerically accurate results for currents. Both of the formalisms can successfully be used to model magnetic resonant tunneling diode structures.Comment: 13 pages and 12 figure

Reasoning about embedded dependencies using inclusion dependencies

The implication problem for the class of embedded dependencies is undecidable. However, this does not imply lackness of a proof procedure as exemplified by the chase algorithm. In this paper we present a complete axiomatization of embedded dependencies that is based on the chase and uses inclusion dependencies and implicit existential quantification in the intermediate steps of deductions

Logical Dreams

We discuss the past and future of set theory, axiom systems and independence results. We deal in particular with cardinal arithmetic

How accurately can subject-specific finite element models predict strains and strength of human femora? Investigation using full-field measurements

Subject-specific finite element models have been proposed as a tool to improve fracture risk assessment in individuals. A thorough laboratory validation against experimental data is required before introducing such models in clinical practice. Results from digital image correlation can provide full-field strain distribution over the specimen surface during in vitro test, instead of at a few pre-defined locations as with strain gauges. The aim of this study was to validate finite element models of human femora against experimental data from three cadaver femora, both in terms of femoral strength and of the full-field strain distribution collected with digital image correlation. The results showed a high accuracy between predicted and measured principal strains (R2=0.93, RMSE=10%, 1600 validated data points per specimen). Femoral strength was predicted using a rate dependent material model with specific strain limit values for yield and failure. This provided an accurate prediction (<2% error) for two out of three specimens. In the third specimen, an accidental change in the boundary conditions occurred during the experiment, which compromised the femoral strength validation. The achieved strain accuracy was comparable to that obtained in state-of-the-art studies which validated their prediction accuracy against 10–16 strain gauge measurements. Fracture force was accurately predicted, with the predicted failure location being very close to the experimental fracture rim. Despite the low sample size and the single loading condition tested, the present combined numerical-experimental method showed that finite element models can predict femoral strength by providing a thorough description of the local bone mechanical response

Generation of 3D shape, density, cortical thickness and finite element mesh of proximal femur from a DXA image

Areal bone mineral density (aBMD), as measured by dual-energy X-ray absorptiometry (DXA), predicts hip fracture risk only moderately. Simulation of bone mechanics based on DXA imaging of the proximal femur, may help to improve the prediction accuracy. Therefore, we collected three (1-3) image sets, including CT images and DXA images of 34 proximal cadaver femurs (set1, including 30 males, 4 females), 35 clinical patient CT images of the hip (set 2, including 27 males, 8 females) and both CT and DXA images of clinical patients (set 3, including 12 female patients). All CT images were segmented manually and landmarks were placed on both femurs and pelvises. Two separate statistical appearance models (SAMs) were built using the CT images of the femurs and pelvises in sets 1 and 2, respectively. The 3D shape of the femur was reconstructed from the DXA image by matching the SAMs with the DXA images. The orientation and modes of variation of the SAMs were adjusted to minimize the sum of the absolute differences between the projection of the SAMs and a DXA image. The mesh quality and the location of the SAMs with respect to the manually placed control points on the DXA image were used as additional constraints. Then, finite element (FE) models were built from the reconstructed shapes. Mean point-to-surface distance between the reconstructed shape and CT image was 1.0mm for cadaver femurs in set 1 (leave-one-out test) and 1.4mm for clinical subjects in set 3. The reconstructed volumetric BMD showed a mean absolute difference of 140 and 185mg/cm3 for set 1 and set 3 respectively. The generation of the SAM and the limitation of using only one 2D image were found to be the most significant sources of errors in the shape reconstruction. The noise in the DXA images had only small effect on the accuracy of the shape reconstruction. DXA-based FE simulation was able to explain 85% of the CT-predicted strength of the femur in stance loading. The present method can be used to accurately reconstruct the 3D shape and internal density of the femur from 2D DXA images. This may help to derive new information from clinical DXA images by producing patient-specific FE models for mechanical simulation of femoral bone mechanics

Osallistamisen polku palveluverkkosuunnittelussa:tapaustutkimus Mellunkylän kaupunkiuudistusalue

Tiivistelmä. Helsingin kaupunki on käynnistänyt uuden kaupunkiuudistuksen mallin, jossa yhtenä pilottialueena toimii Mellunkylä. Kaupunkiuudistuksella pyritään hillitsemään segregaatiokehitystä, edistämään alueiden elinvoimaisuutta ja mahdollistamaan laadukas täydennysrakentaminen. Mellunkylän kaupunkiuudistusalueen palveluverkkosuunnittelussa Helsingin kaupunki haluaa kiinnittää yhä enemmän huomiota kuntalaisten osallistamiseen ja vuorovaikutuksen lisäämiseen. Palveluverkkosuunnittelun osallistamista toteutetaan toimialakohtaisesti, mihin Helsingin kaupunki tarvitsee muutosta ja kehitystä: yhteistyötä ja yhteisymmärrystä. Tutkielman tavoitteena on tarkastella Helsingin kaupungin palveluverkkosuunnittelun osallistamiskäytäntöjä sekä niiden kehittämistarpeita etenkin Helsingin kaupungin ja sen eri toimialojen näkökulmista. Erityisesti tavoitteena on saada tietoa siitä, mitä osallistamismenetelmiä Helsingin kaupunki käyttää palveluverkkosuunnittelussa, ovatko menetelmät oikea-aikaisia, riittäviä ja hallittuja ja miten osallistamista palveluverkkosuunnittelussa voitaisiin kehittää. Tutkimuksen aineisto koostui Helsingin kaupungin palveluverkkosuunnittelun ja osallistamisen asiantuntijoille tehdystä kyselystä sekä yhteisistä palavereista. Kyselyaineisto muodosti tutkielmassa kuvaa toimialakohtaisista käsityksistä osallistamisesta ja osallistamismenetelmistä. Analysoin aineiston laadullisella sisällönanalyysillä ja vertasin tuloksia Arnsteinin (1969) osallistamisasteikkoon. Tulosten perusteella osallistamista palveluverkkosuunnittelussa tulisi kehittää etenkin prosessin alkuvaiheessa, mutta osallisuutta pitäisi saada jokaiseen prosessin vaiheeseen. Osallistamisen tuotoksia pitäisi jakaa tehokkaammin ja koordinoidummin Helsingin kaupungin toimialojen välillä. Tutkielman tuloksien perusteella osallistamista palveluverkkosuunnittelussa voitaisiin kehittää asiantuntijoiden roolien selkeyttämisellä ja verkostomaisella yhteistyöllä. Palveluverkkosuunnittelun osallistamista voitaisiin edistää myös yhteisellä toimintamallilla, sekä yhteisellä alustalla, jonka kautta eri toimialat voisivat hyödyntää osallistamisen kautta saatuja tuotoksia ja tietoja sekä kyetä ennakoimaan tulevia osallistamistapahtumia. Konkreettisina kehitysehdotuksina nousivat esille palveluverkkosuunnittelun osallistumis- ja arviointisuunnitelma sekä palveluverkkosuunnittelun vuosikello