525 research outputs found
Circular Coloring of Random Graphs: Statistical Physics Investigation
Circular coloring is a constraints satisfaction problem where colors are
assigned to nodes in a graph in such a way that every pair of connected nodes
has two consecutive colors (the first color being consecutive to the last). We
study circular coloring of random graphs using the cavity method. We identify
two very interesting properties of this problem. For sufficiently many color
and sufficiently low temperature there is a spontaneous breaking of the
circular symmetry between colors and a phase transition forwards a
ferromagnet-like phase. Our second main result concerns 5-circular coloring of
random 3-regular graphs. While this case is found colorable, we conclude that
the description via one-step replica symmetry breaking is not sufficient. We
observe that simulated annealing is very efficient to find proper colorings for
this case. The 5-circular coloring of 3-regular random graphs thus provides a
first known example of a problem where the ground state energy is known to be
exactly zero yet the space of solutions probably requires a full-step replica
symmetry breaking treatment.Comment: 19 pages, 8 figures, 3 table
Examining Collaboration in Interdisciplinary Product Development Focusing on Dependencies
Product development in manufacturing industry is characterized by intense collaboration need of various stakeholders. Increasing integration of disciplines in modern products makes it more and more a challenge to arrange collaboration efficiently and effectively. Process and product characteristics as well as the architecture of information systems used in product development have to be considered. This paper introduces a methodology for the design of collaboration situations based on principles of system analysis. First, a collaboration situation is defined and modelled regarding constituent elements in the domains process, product and system. Second, a description model for dependencies in these domains is developed. Morphological analysis was applied to derive features and characteristics of the model. Third, an improvement approach to optimize a given collaboration situation is depicted. The improvement approach comprises a sensitivity model, which explicates causal relations between the dependency features. The methodology is applied to a case study from manufacturing industry
Urban Heritage under Transition: Theingyi Zay in Yangon / Myanmar
Heritage under Transition: Theingyi Zay, Yangon, Myanmar
By Christian Guenther
The focus of this study lies at the Thein Gyi Zay, a market colonially established in downtown Yangon by Indians under British legitimation in the 19th century which is still a focal point for local and regional, long term as well as short term day to day trade and a significant representative of the colonial layer in Myanmar.
Beyond its original function of trade the social function of Thein Gyi Zay is of immense importance. As Yangon can be regarded as melting pot for a variety of ethnical groups and religions the Thein Gyi Zay market reflects this heterogeneity because it is operated and used by people with Burmese, Indian and Chinese ancestry as well as Buddhist, Hindu, Islamic, and Christian religious backgrounds. While the downtown area of Yangon is characterized by ethnical segregation, the Thein Gyi Zay assembles a mixture of this heterogeneity in a very dense space. Furthermore, it also reflects to a great amount the socio economic situations of Yangonâs citizens as people of all social classes come here to follow their business.
Since the initialising of transition in Myanmar in 1988 through political and economic reorganization this process has reached a stage of unprecedented velocity which sets a volatile frame for urban heritage within the context of urban development in Yangon and consequently for the future of Thein Gyi Zay, as well. This development leads to a variety of urban planning challenges because it demands a readjustment of local infrastructure (traffic, electricity, social housing, etc.).
In order to approach this complex environment I have conducted field work during two month this summer which compared the statuses of the market in 2005 and 2012 by mapping commodity groups at the market. However, it has not been possible to identify significant trends in change but that the market is very vital. In a second step interviews at the market investigated reasons for changes from an economic and social perspective in order to prepare for future developments and demands. Business is declining as interview partners complained while the social value has been regarded as mostly stable. Future scenarios drafted from wishes and demands depict a necessary upgrading of the market while expecting a possible displacement of local communities
Characterization of in vivo chemoresistant human hepatocellular carcinoma cells with transendothelial differentiation capacities
Background: Chemotherapeutic treatment of hepatocellular carcinoma often leads to chemoresistance during therapy or upon relapse of tumors. For the development of better treatments a better understanding of biochemical changes in the resistant tumors is needed. In this study, we focus on the characterization of in vivo chemoresistant human hepatocellular carcinoma HUH-REISO established from a metronomically cyclophosphamide (CPA) treated HUH7 xenograft model. Methods: SCID mice bearing subcutaneous HUH7 tumors were treated i.p. with 75 mg/kg CPA every six days. Tumors were evaluated by immunohistochemistry, a functional blood-flow Hoechst dye assay, and qRT-PCR for ALDH-1, Notch-1, Notch-3, HES-1, Thy-1, Oct-4, Sox-2 and Nanog mRNA levels. Cell lines of these tumors were analyzed by qRT-PCR and in endothelial transdifferentiation studies on matrigel. Results: HUH-REISO cells, although slightly more sensitive against activated CPA in vitro than parental HUH-7 cells, fully retained their in vivo CPA chemoresistance upon xenografting into SCID mice. Histochemical analysis of HUH-REISO tumors in comparison to parental HUH-7 cells and passaged HUH-PAS cells (in vivo passaged without chemotherapeutic pressure) revealed significant changes in host vascularization of tumors and especially in expression of the tumor-derived human endothelial marker gene PECAM-1/CD31 in HUH-REISO. In transdifferentiation studies with limited oxygen and metabolite diffusion, followed by a matrigel assay, only the chemoresistant HUH-REISO cells exhibited tube formation potential and expression of human endothelial markers ICAM-2 and PECAM-1/CD31. A comparative study on stemness and plasticity markers revealed upregulation of Thy-1, Oct-4, Sox-2 and Nanog in resistant xenografts. Under therapeutic pressure by CPA, tumors of HUH-PAS and HUH-REISO displayed regulations in Notch-1 and Notch-3 expression. Conclusions: Chemoresistance of HUH-REISO was not manifested under standard in vitro but under in vivo conditions. HUH-REISO cells showed increased pluripotent capacities and the ability of transdifferentiation to endothelial like cells in vitro and in vivo. These cells expressed typical endothelial surface marker and functionality. Although the mechanism behind chemoresistance of HUH-REISO and involvement of plasticity remains to be clarified, we hypothesize that the observed Notch regulations and upregulation of stemness genes in resistant xenografts are involved in the observed cell plasticity
Supporting Flexible Processes with Adaptive Workflow and Case Handling
Workflow management technology has profoundly transformed the way complex tasks are being handled in modern, large-scale organizations. However, it is mostly those systemsâ inherent lack of flexibility that hinders their broad acceptance, and that is perceived as annoyance by users. In this context, Adaptive Process Management and Case Handling provide two very different paradigms, which both attempt to make process management more flexible and user-friendly. In this paper, we compare strengths and weaknesses of these two paradigms, and point out situations in which each is particularly appropriate. We further outline ways, in which either technology can be enhanced by crucial concepts from the other. This integration of flexibility approaches has the potential to remedy fundamental problems still present in each technology on its own
Tribological Performance of Additively Manufactured AISI H13 Steel in Different Surface Conditions
The tropical forest and fire emissions experiment: laboratory fire measurements and synthesis of campaign data
International audienceAs part of the Tropical Forest and Fire Emissions Experiment (TROFFEE), tropical forest fuels were burned in a large, biomass-fire simulation facility and the smoke was characterized with open-path Fourier transform infrared spectroscopy (FTIR), proton-transfer reaction mass spectrometry (PTR-MS), gas chromatography (GC), GC/PTR-MS, and filter sampling of the particles. In most cases, about one-third of the fuel chlorine ended up in the particles and about one-half remained in the ash. About 50% of the mass of non-methane organic compounds (NMOC) emitted by these fires could be identified with the available instrumentation. The lab fire emission factors (EF, g compound emitted per kg fuel burned) were coupled with EF obtained during the TROFFEE airborne and ground-based field campaigns. This revealed several types of EF dependence on parameters such as the ratio of flaming to smoldering combustion and fuel characteristics. The synthesis of data from the different TROFFEE platforms was also used to derive EF for all the measured species for both primary deforestation fires and pasture maintenance fires ? the two main types of biomass burning in the Amazon. Many of the EF are larger than those in widely-used earlier work. This is mostly due to the inclusion of newly-available, large EF for the initially-unlofted smoldering emissions and the assumption that these emissions make a significant contribution (~40%) to the total emissions from pasture fires. The TROFFEE EF for particles with aerodynamic diameter 2.5) is 14.8 g/kg for primary deforestation fires and 18.7 g/kg for pasture maintenance fires. These EFPM2.5 are significantly larger than a previous recommendation (9.1 g/kg) and lead to an estimated pyrogenic primary PM2.5 source for the Amazon that is 84% larger. Regional through global budgets for biogenic and pyrogenic emissions were roughly estimated. Coupled with previous measurements of secondary aerosol growth in the Amazon and source apportionment studies, the regional budgets suggest that ~5% of the total mass of the regionally generated NMOC end up as secondary organic aerosol within the Amazonian boundary layer within 1?3 days. The global budgets confirm that biogenic emissions and biomass burning are the two largest global sources of NMOC with an estimated production of approximately 1000 and 500 Tg/yr, respectively. It follows that plants and fires may also be the two main global sources of secondary organic aerosol. A limited set of emission ratios (ER) is given for sugar cane burning, which may help estimate the air quality impacts of burning this major crop, which is often grown in densely populated areas
Consequences of Marketing Asset AccountabilityâA Natural Experiment
Marketing scholars have extensively studied marketing's effect on firm value and have developed metrics and dashboards to help establish marketing accountability. However, empirical evidence of marketing accountability's specific outcomes is scarce and mainly derived from surveys. It also lacks consideration of outcomes beyond the marketing function's standing in the firm, thus overlooking possible downsides and outcomes with regard to external stakeholders such as investors. Using a natural experimentâAustralia's change from a nonrestrictive to a restrictive accounting regimeâthis study investigates how accountability for the financial value of marketing assets (marketing asset accountability) affects a firm's marketing management focus on short-term vis-Ă -vis long-term marketing efficiency, its cost of capital, and the degree to which its stock price reflects actual future performance (i.e., stock price informativeness). The results show that marketing asset accountability improves long-term marketing efficiency, reduces cost of equity, and improves stock price informativeness, but does not consistently affect short-term marketing efficiency and cost of debt. Moreover, although marketing-intensive firms are commonly assumed to benefit most from marketing asset accountability, this is not the case. These results have implications for researchers, managers, and public policy decision makers. </jats:p
Space and Ground Based Pulsation Data of Eta Bootis Explained with Stellar Models Including Turbulence
The space telescope MOST is now providing us with extremely accurate low
frequency p-mode oscillation data for the star Eta Boo. We demonstrate in this
paper that these data, when combined with ground based measurements of the high
frequency p-mode spectrum, can be reproduced with stellar models that include
the effects of turbulence in their outer layers. Without turbulence, the l=0
modes of our models deviate from either the ground based or the space data by
about 1.5-4.0 micro Hz. This discrepancy can be completely removed by including
turbulence in the models and we can exactly match 12 out of 13 MOST frequencies
that we identified as l=0 modes in addition to 13 out of 21 ground based
frequencies within their observational 2 sigma tolerances. The better agreement
between model frequencies and observed ones depends for the most part on the
turbulent kinetic energy which was taken from a 3D convection simulation for
the Sun.Comment: 13 pages, 7 figures, ApJ in pres
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