963 resultados para Weak ties
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This paper seeks to advance the theory and practice of the dynamics of complex networks in relation to direct and indirect citations. It applies social network analysis (SNA) and the ordered weighted averaging operator (OWA) to study a patent citations network. So far the SNA studies investigating long chains of patents citations have rarely been undertaken and the importance of a node in a network has been associated mostly with its number of direct ties. In this research OWA is used to analyse complex networks, assess the role of indirect ties, and provide guidance to reduce complexity for decision makers and analysts. An empirical example of a set of European patents published in 2000 in the renewable energy industry is provided to show the usefulness of the proposed approach for the preference ranking of patent citations.
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The objective of this study is to demonstrate using weak form partial differential equation (PDE) method for a finite-element (FE) modeling of a new constitutive relation without the need of user subroutine programming. The viscoelastic asphalt mixtures were modeled by the weak form PDE-based FE method as the examples in the paper. A solid-like generalized Maxwell model was used to represent the deforming mechanism of a viscoelastic material, the constitutive relations of which were derived and implemented in the weak form PDE module of Comsol Multiphysics, a commercial FE program. The weak form PDE modeling of viscoelasticity was verified by comparing Comsol and Abaqus simulations, which employed the same loading configurations and material property inputs in virtual laboratory test simulations. Both produced identical results in terms of axial and radial strain responses. The weak form PDE modeling of viscoelasticity was further validated by comparing the weak form PDE predictions with real laboratory test results of six types of asphalt mixtures with two air void contents and three aging periods. The viscoelastic material properties such as the coefficients of a Prony series model for the relaxation modulus were obtained by converting from the master curves of dynamic modulus and phase angle. Strain responses of compressive creep tests at three temperatures and cyclic load tests were predicted using the weak form PDE modeling and found to be comparable with the measurements of the real laboratory tests. It was demonstrated that the weak form PDE-based FE modeling can serve as an efficient method to implement new constitutive models and can free engineers from user subroutine programming.
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One of the extraordinary aspects of nonlinear wave evolution which has been observed as the spontaneous occurrence of astonishing and statistically extraordinary amplitude wave is called rogue wave. We show that the eigenvalues of the associated equation of nonlinear Schrödinger equation are almost constant in the vicinity of rogue wave and we validate that optical rogue waves are formed by the collision between quasi-solitons in anomalous dispersion fiber exhibiting weak third order dispersion.
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2000 Mathematics Subject Classification: 47H10, 54E15.
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2000 Mathematics Subject Classification: 60J27, 60K25.
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2000 Mathematics Subject Classification: 60G18, 60E07
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2002 Mathematics Subject Classification: 35S05, 47G30, 58J42.
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The purpose of this article is to investigate in which ways multi-level actor cooperation advances national and local implementation processes of human rights norms in weak-state contexts. Examining the cases of women’s rights in Bosnia and Herzegovina and children’s rights in Bangladesh, we comparatively point to some advantages and disadvantages cooperative relations between international organisations, national governments and local NGOs can entail. Whereas these multi-level actor constellations (MACs) usually initiate norm implementation processes reliably and compensate governmental deficits, they are not always sustainable in the long run. If international organisations withdraw support from temporary missions or policy projects, local NGOs are not able to perpetuate implementation activities if state capacities have not been strengthened by MACs. Our aim is to highlight functions of local agency within multi-level cooperation and to critically raise sustainability issues in human rights implementation to supplement norm research in International Relations.
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2000 Mathematics Subject Classification: 54H25, 47H10.
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We study theoretically and numerically the dynamics of a passive optical fiber ring cavity pumped by a highly incoherent wave: an incoherently injected fiber laser. The theoretical analysis reveals that the turbulent dynamics of the cavity is dominated by the Raman effect. The forced-dissipative nature of the fiber cavity is responsible for a large diversity of turbulent behaviors: Aside from nonequilibrium statistical stationary states, we report the formation of a periodic pattern of spectral incoherent solitons, or the formation of different types of spectral singularities, e.g., dispersive shock waves and incoherent spectral collapse behaviors. We derive a mean-field kinetic equation that describes in detail the different turbulent regimes of the cavity and whose structure is formally analogous to the weak Langmuir turbulence kinetic equation in the presence of forcing and damping. A quantitative agreement is obtained between the simulations of the nonlinear Schrödinger equation with cavity boundary conditions and those of the mean-field kinetic equation and the corresponding singular integrodifferential reduction, without using adjustable parameters. We discuss the possible realization of a fiber cavity experimental setup in which the theoretical predictions can be observed and studied.
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Miért van a magyar gazdaság hasonlóan kritikus helyzetben, mint a rendszerváltást megelőző időkben? Miért nem sikerül az eladósodást megállítani, a gazdaságot konszolidálni, és fenntartható növekedési pályára állítani? Ennek közvetlen okát a szerzők a fejlődés féloldalasságában és a duális gazdasági szerkezetben látják. A piacgazdasági intézmények bevezetése ugyanis nem járt együtt az egész gazdaságot (vagy legalábbis annak nagy részét) átfogó, a tudásvezérelt információgazdaság felé mutató, gyors fejlődéssel. Számos indikátor azt jelzi, hogy az ország lemaradt a nemzetközi innovációs versenyben. Az innovációk elégtelensége azonban nem véletlen, nem exogén adottság, hanem a formális piaci intézmények mögött meghúzódó valós intézményi berendezkedéssel, a gazdaságban ténylegesen észlelhető magatartásmintákkal magyarázható. A piacgazdasági intézmények és jogi keretek, amelyek elvileg lehetőséget adnak az erőforrásokhoz való szabad és nyílt hozzáférésre, csak részben töltődtek meg tartalommal. Az országban még mindig meglehetősen korlátozott a sikeres belépés lehetősége a piaci és a politikai arénába, azaz a magyar társadalom - a north-i terminológiával élve - "korlátozott hozzáférésre alapozott társadalomként" írható le. Az a tény, hogy a piaci szereplők esélyei az államhoz és intézményeihez fűződő kapcsolatoktól függően nagyban különböznek egymástól, és a gazdasági szereplők rendszerszerűen használják e kapcsolatokat járadékszerzésre, lefojtja az innovációt, és újra és újra megakasztja a fejlődést. / === / Why is Hungary's economy still in a critical state similar to the one before the change of system? Why is the indebtedness not being halted, the economy consolidated or vital structural reforms performed? The authors see the direct cause in lopsided development and a dual economic structure. The introduction of market economic institutions was not followed by rapid, overall development towards a knowledge-led, information economy. Several indicators show how Hungary has fallen behind in competition for international innovation. The inadequacy is not a fortuitous, exogenous attribute, but explicable in terms of a real institutional setup underlying the formal market institutions, and of actual behaviour patterns found in the economy. Only in part has substance been gained by the institutions and legal frames of a market economy that theoretically would provide free and open access to resources. The scope for successful entry into the market or political arena remains very narrow, so that in Douglass North's terms, Hungary's is still "a society based on restricted access." Innovation is stifled and development repeatedly impeded by the fact that market players' chances differ widely depending on their connections with the state and its institutions and such connections are used regularly in rent-seeking.
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This paper addresses a problem with an argument in Kranich, Perea, and Peters (2005) supporting their definition of the Weak Sequential Core and their characterization result. We also provide the remedy, a modification of the definition, to rescue the characterization.
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A „földrajzi munkamegosztás” vagy „elhelyezkedés probléma” arra a kérdésre utal, miért alakulnak ki egy-egy gazdasági tevékenységre szakosodott földrajzi egységek, regionális gazdasági rendszerek. A hagyományos közgazdasági megközelítések a területek racionálisan kalkulálható komparatív előnyeit, a nyersanyagok vagy a piac közelségét, infrastrukturális adottságokat, útfüggőséget stb. szokták hangsúlyozni. A tanulmány szerzője a társadalmi kapcsolatok jelentőségét emeli ki, azt sugallja, hogy a területi specializálódás az egymással kapcsolatban álló, hasonlóan specializálódott többi szereplő nyomására alakul ki. A hipotézist két külföldön végzett eset tanulmány tapasztalatai alapján járja körül. ______________________ The question of "regional economic systems", "geographical division of labour" or "location problem" has an important literature. Economic approaches emphasize the rationally calculated advantages of the specialized industrial areas: the benefit of the exploitation of discovered resources, more cooperative relations, etc. The paper stresses the role of social networks in the location problem: economically specialized areas formed because of the suggestions and tips of connected enterprises, cooperative partners. The hypothesis is based on the experiences of two case studies, made in a Peruvian rural area and a Mexican modern industrial area.
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This article investigates whether the strength of formal professional relationships between general practitioners (GPs) and specialists (SPs) affects either the health status of patients or their pharmacy costs. To this end, it measures the strength of formal professional relationships between GPs and SPs through the number of shared patients and proxies the patient health status by the number of comorbidities diagnosed and treated. In strong GP–SP relationships, the patient health status is expected to be high, due to efficient care coordination, and the pharmacy costs low, due to effective use of resources. To test these hypotheses and compare the characteristics of the strongest GP–SP connections with those of the weakest, this article concentrates on diabetes—a chronic condition where patient care coordination is likely important. Diabetes generates the largest shared patient cohort in Hungary, with the highest traffic of specialist medication prescriptions. This article finds that stronger ties result in lower pharmacy costs, but not in higher patient health statuses. Key points for decision makers • The number of shared patients may be used to measure the strength of formal professional relationships between general practitioners and specialists. • A large number of shared patients indicates a strong, collaborative tie between general practitioners and specialists, whereas a low number indicates a weak, fragmented tie. • Tie strength does not affect patient health—strong, collaborative ties between general practitioners and specialists do not involve better patient health than weak, fragmented ties. • Tie strength does affect pharmacy costs—strong, collaborative ties between general practitioners and specialists involve significantly lower pharmacy costs than weak, fragmented ties. • Pharmacy costs may be reduced by lowering patient care fragmentation through channelling a general practitioner’s patients to a small number of specialists and increasing collaboration between general practitioner and specialists. • Limited patient choice is financially more beneficial than complete freedom of choice, and no more detrimental to patient health.
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Arra a kérdésre keressük a választ, hogy a szoros háziorvosi-szakorvosi szakmai kapcsolatoknak van-e hatásuk a betegek gyógyszerkiadására, illetve egészségi állapotára. Az orvosok közötti szakmai kapcsolatok szorosságát a közösen gondozott betegek száma alapján határoztuk meg, míg a betegek egészségügyi állapotát a diagnosztizált és kezelt társbetegségek számával mértük. Hipotézisünk egyrészt az volt, hogy a hatékonyabb koordinációnak köszönhetően a szoros kapcsolatban kezelt betegek jobb egészségi állapotúak, másrészt kezelésük az erőforrások hatékonyabb felhasználása miatt kisebb gyógyszerköltséggel jár. E két hipotézist a cukorbetegekre teszteltük. Azért esett erre a krónikus betegségre a választásunk, mert itt a háziorvosok és a szakorvosok együttműködése elsődleges fontosságú. Magyarországon a cukorbetegek esetében a legnagyobb a közösen kezelt betegek populációja, valamint itt a legmagasabb a szakorvosi javaslatra felírt háziorvosi receptek száma. Azt az eredményt kaptuk, hogy a szoros kapcsolatban kezelt betegek nem rendelkeznek sem jobb, sem rosszabb egészségi állapottal, miközben a kapcsolódó gyógyszerkiadásuk szignifikánsan alacsonyabb. ____ The article considers whether strong formal professional relations between GPs and specialists in shared care affect either the health of patients or the pharmacy costs they incur. The strength of such relations is measured by the number of shared patients; patient health is proxied by number of co-morbidities diagnosed and treated. The first hypothesis is that patients treated amid strong GP-specialist relations have better health status than those treated amid weak ones, due to enhanced efficiency of care coordination. The second is that patients treated in such strong relations incur lower pharmacy costs high numbers of shared patients are assumed to promote appropriate, effective use of resources. The article tests these hypotheses and compares the outcomes of the strongest and weakest GP-specialist relations through the example of diabetes, a chronic condition where patient-care coordination is important. Diabetes generates the largest shared patient cohort in Hungary, with the highest number of specialist medication prescriptions. This article finds that stronger ties result in significantly lower pharmacy costs, but not a higher patient health status.