4,809 research outputs found
Learning visual docking for non-holonomic autonomous vehicles
This paper presents a new method of learning visual docking skills for non-holonomic vehicles by direct interaction with the environment. The method is based on a reinforcement algorithm, which speeds up Q-learning by applying memorybased sweeping and enforcing the âadjoining propertyâ, a filtering mechanism to only allow transitions between states that satisfy a fixed distance. The method overcomes some limitations of reinforcement learning techniques when they are employed in applications with continuous non-linear systems, such as car-like vehicles. In particular, a good approximation to the optimal
behaviour is obtained by a small look-up table. The algorithm is tested within an image-based visual servoing framework on a docking task. The training time was less than 1 hour on the real vehicle. In experiments, we show the satisfactory performance of the algorithm
Can Labor Market Imperfections Cause Overprovision of Public Inputs?
In a model where trade unions dominate the labor market, a relationship is derived between the rate of unemployment and the provision of a public input in the production. This relationship implies that for conventional rates of unemployment, the public input will be overprovided compared to the first-best level.Public Inputs, Trade Unions.
Calculation of nuclear matrix elements in neutrinoless double electron capture
We compute nuclear matrix elements for neutrinoless double electron capture
on Gd, Er and W nuclei. Recent precise mass
measurements for these nuclei have shown a large resonance enhancement factor
that makes them the most promising candidates for observing this decay mode. We
use an advanced energy density functional method which includes beyond
mean-field effects such as symmetry restoration and shape mixing. Our
calculations reproduce experimental charge radii and values predicting
a large deformation for all these nuclei. This fact reduces significantly the
values of the NMEs leading to half-lives larger than years for the
three candidates
Using foresight in business ecosystems and innovation ecosystems
In the even faster changing and increasingly uncertain environment in which corporates, star-ups, public sector players and governmental institutions operate, the importance of ecosystems as a form of organization is growing and will further grow in the future. Ecosystems are an emerging research topic. Due to the very complex composition, structure and dynamics of ecosystems, the challenges of foresight in ecosystems multiply in comparison to foresight in more simple types of organization.
This research explores how foresight can contribute to the design, orchestration and development of business ecosystems and innovation ecosystems, and how it could be utilized in a more effective and impactful way. The main objective is to add to the body of empirical research of foresight in business ecosystems and innovation ecosystems and to contribute with insights to further development of foresight in this novel, complex and challenging collaboration environment.
The study is qualitative. Secondary data has been collected through a literature analysis of academic research articles, books and existing case studies. Based on that analysis semi-structured theme interviews were designed and conducted with highly qualified researchers and practitioners in order to gather primary empiric data. The data has been analyzed and interpreted with aid of relevant ecosystem theory and foresight theory.
The results of this research emphasize the benefits of foresight along the lifecycle of business ecosystems and innovation ecosystems, from their design to their development and transformation. Moreover challenges and best practices of foresight related to foresight design for ecosystems, limited foresight capabilities, ecosystem complexity, ecosystem-specific business aspects and ecosystem dynamics are discussed.
It can be concluded that ecosystems demand from foresight a high degree of customization and understanding of the context, structure, players, dynamics and lifecycle phases of the particular ecosystem. To improve the credibility of foresight and foresight capabilities as well, more empiric research and case studies of successful foresight in ecosystems are required.NykypÀivÀnÀ yritykset, startup-yritykset, julkisen sektorin toimijat, sekÀ hallituksen alaiset instituutiot toimivat yhÀ nopeammin muuttuvassa ja epÀvarmemmassa ympÀristössÀ. Sen seurauksena ekosysteemien merkitys organisaatiomuotona kasvaa, ja tulee yhÀ kasvamaan tulevaisuudessa. Ekosysteemit ovat nouseva tutkimusaihe. Ekosysteemien koostumus, rakenne ja dynamiikka ovat hyvin monimutkaisia ja tÀmÀ johtaa siihen, ettÀ ennakoinnin haasteet ekosysteemeissÀ moninkertaistuvat.
TÀmÀ Pro gradu-tutkielma kÀsittelee ennakoinnin mahdollisia hyötyjÀ liiketoiminta- ja innovaatioekosysteemien suunnittelussa, johtamisessa ja kehittÀmisessÀ. Sen lisÀksi se tutkii, miten ennakointia voidaan kÀyttÀÀ tehokkaammin ja sen vaikuttavuus voidaan maksimoida. PÀÀtavoitteena on myötÀvaikuttaa empiiriseen tutkimukseen alueella ennakointi liiketoiminta- ja innovaatioekosysteemeissÀ, sekÀ tuoda esille oivalluksia, joista on hyötyÀ kehittÀessÀ ennakointia tÀssÀ uudessa, kompleksisessa ja haastavassa yhteistyöympÀristössÀ.
Tutkielma on luonteeltaan kvalitatiivinen. Sekundaaridata on kerÀtty akateemisten artikkeleiden, kirjojen ja olemassa olevien esimerkkitapausten kirjallisuuskatsauksen avulla. Sekundaaridatan analyysin perustella on suunniteltu ja toteutettu teemahaastatteluja hyvin pÀtevien tutkijoiden ja ammattilaisten kanssa primaaridatan kerÀÀmiseen. Data on analysoitu ja tulkittu relevanttien ekosysteemiteorioiden ja ennakointiteorian avulla.
Tutkimustulokset korostavat ennakoinnin hyödyt liiketoiminta- ja innovaatioekosysteemien elinkaaren aikana, niiden suunnittelusta niiden kehittÀmiseen ja muuntamiseen. Tutkielma tuo esille myös ennakoinnin erityyppisiÀ haasteita ja parhaita kÀytÀntöjÀ liiketoiminta- ja innovaatioekosysteemeissÀ liittyen ennakoinnin suunnitteluun, ennakointiosaamisen puutteisiin, monimutkaisuuteen, liiketoimintaan ja dynamiikkaan.
Tutkielman loppupÀÀtelmÀ on, ettÀ ekosysteemi edellyttÀÀ ennakoinnin rÀÀtÀlöintiÀ ja sitÀ varten ekosysteemin kontekstin, rakenteen, toimijoiden, dynamiikan ja elinkaaren ymmÀrtÀmistÀ. Ennakointiosaamisen ja ennakoinnin uskottavuuden parantamiseen tarvitaan lisÀÀ empiiristÀ tutkimusta ja esimerkkitapauksia onnistuneesta ennakoinnista ekosysteemeissÀ
Vertical externalities with lump-sum taxes: how much difference does unemployment make?
This paper analyses how the existence of unemployment affects the conventional approach to vertical externalities. We discuss the optimality rule for the provision of public inputs both in a unitary and in a federal state. Our findings indicate that decentralising spending responsability on public inputs in the presence of unemployment allows output to be closer to the first best level. Moreover, we describe the inability of the federal government, behaving as a Stackelberg leader, to replicate the unitary outcome, unless there are new policy instruments at government's disposal
EVALUACIĂN DE LA CALIDAD DE VIDA DE ACUERDO CON LA ESCALA DE WOMAC EN PACIENTES CON DIAGNOSTICO DE ENFERMEDAD DEGENERATIVA ARTICULAR DE RODILLA POSTOPERADOS DE ARTROPLASTIA DE RODILLA DEL CENTRO MĂDICO ISSEMYM ECATEPEC.
A push-pull unsymmetrical subphthalocyanine dimer
Unsymmetrical subphthalocyanine fused dimers have been prepared from appropriate ortho-dinitrile SubPc precursors. In particular, either electron-donating or electron-accepting substituents have been introduced on each SubPc constituent unit, resulting in unprecedented pushâpull Ï-extended curved aromatic macrocycles. From fluorescence experiments in solvents of different polarity we conclude a dual fluorescence, namely a delocalized singlet excited state (1.73 eV) and a polarized charge transfer state (<1.7 eV). Pump probe experiments corroborate the dual nature of the fluorescence. On one hand, the delocalized singlet excited state gives rise to a several nanosecond lasting intersystem crossing yielding the corresponding triplet excited state. On the other hand, the polarized charge transfer state deactivates within a few picosesonds. Visualization of the charge transfer state was accomplished by means of molecular modeling with a slight polarization of the HOMO towards the electron donor and of the LUMO towards the electron acceptor
Graphitization of amorphous carbons: A comparative study of interatomic potentials
We perform a comparative study of six common carbon interatomic potentials: Tersoff, REBO-II, ReaxFF, EDIP, LCBOP-I and COMB3. To ensure fair comparison, all the potentials are used as implemented in the molecular dynamics package LAMMPS. Using the liquid quenching method we generate amorphous carbons at different densities, and subsequently anneal at high temperature. The amorphous carbon system provides a critical test of the transferability of the potential, while the annealing simulations illustrate the graphitization process and test bond-making and -breaking. A wide spread of behavior is seen across the six potentials, with quantities such as sp2 fraction, radial distribution function, morphology, ring statistics, and 002 reflection intensity differing considerably. While none of the potentials is perfect, some perform particularly poorly. The lack of transferability can be traced to the details of the functional form, suggesting future directions in the development of carbon potentials
Water rituals on the Bravo/Grande River: a transnational political and ecological inheritance
The Mexico-US border region is home to a particular hydraulic tradition with important social, cultural and environmental dimensions. This article discusses the ways that European, indigenous and mestizo colonists from central Mexico reshaped the borderlands as they molded Mesoamerican irrigation systems to the arid landscapes of the region. Small-scale irrigation systems conserve humidity and protect against heat and cold, and allow the reproduction of plants that constitute an important source of biodiversity, as well as a viable economic strategy for small-scale farmers. Religious festivals and rituals, together with social organizations, bring people together in communities around these irrigation systems. The author argues that these traditions are alive and well in many places, and constitute a shared inheritance of sustainable adaptation for people on both sides of the national-state divide.
Key words: Mexico-US border, Rio Bravo/Grande, water rituals, acequia
Effects of carbohydrate applications on growth and vitality of live oak (Quercus virginiana)
Urban forests grow in stressful environments that can have negativerepercussions on tree energy reserves. The goal of this research was to evaluate theimpact of exogenously applied carbohydrates on growth and vitality of live oaks(Quercus virginiana P. Miller). An initial study focused on carbohydrate partitioningrevealed that annual mean glucose concentration in leaf tissues (49.55 mg·g-1 DW) wasalmost double that in twigs, trunks, or roots. Starch concentrations in roots and trunks(38.98 and 38.22 mg·g-1 DW of glucose, respectively) were higher during the dormantseason and approximately three times the concentrations found in other tissues. Aninvestigation of the effects of exogenous soil applications of glucose and starch on soilmicrobial activity revealed no significant differences using recoverable viable microbes.However, soil respiration was significantly increased (P<0.05) by glucose a week afterapplication, while higher starch concentrations (120 g·L-1) significantly increased(P<0.05) soil respiration after the fourth week. Although tree soil drenched withcarbohydrates in a different study showed significantly (P<0.05) greener leaf color, higher chlorophyll fluorescence, and increased soil respiration at higher concentrationsof starch (120 g·L-1), no significant differences were observed in photosynthesis or trunk,canopy, or root growth. Analysis of 13C signatures was unable to detect uptake ofexogenous carbohydrates. For trunk-injected trees with glucose and sucrose, trunkgrowth was significantly (P<0.05) increased by carbohydrate supplementation.Differences were also found in twig glucose content, root starch content, and chlorophyllfluorescence among overall concentration means. A study to compare field diagnostictools with carbohydrate laboratory analysis established that a portable blood glucosemeter can be used to measure glucose content in trees. However, ohmmeter,refractometer, chlorophyll fluorescence spectrometer, and iodine staining results did notcorrelate well with laboratory analysis of carbohydrate concentrations. Results fromthese studies reveal that soil applied carbohydrates can greatly increase soil microbialactivity, provide evidence that trunk-injected carbohydrates may improve growth andvitality of live oaks, and provide a new field diagnostic tool to increase the efficiency ofmeasuring carbohydrates in trees
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