172 research outputs found

    Sprinklers: A Randomized Variable-Size Striping Approach to Reordering-Free Load-Balanced Switching

    Full text link
    Internet traffic continues to grow exponentially, calling for switches that can scale well in both size and speed. While load-balanced switches can achieve such scalability, they suffer from a fundamental packet reordering problem. Existing proposals either suffer from poor worst-case packet delays or require sophisticated matching mechanisms. In this paper, we propose a new family of stable load-balanced switches called "Sprinklers" that has comparable implementation cost and performance as the baseline load-balanced switch, but yet can guarantee packet ordering. The main idea is to force all packets within the same virtual output queue (VOQ) to traverse the same "fat path" through the switch, so that packet reordering cannot occur. At the core of Sprinklers are two key innovations: a randomized way to determine the "fat path" for each VOQ, and a way to determine its "fatness" roughly in proportion to the rate of the VOQ. These innovations enable Sprinklers to achieve near-perfect load-balancing under arbitrary admissible traffic. Proving this property rigorously using novel worst-case large deviation techniques is another key contribution of this work

    Toward the Theoretical Constructs of East Asian Cultural Psychology

    Get PDF
    The core values of traditional Chinese Confucian culture such as “five virtues”, “five cardinal relationships”, and the thought of “golden mean” exert significant influence on East Asian culture, including Chinese, Japanese, and Korean cultures. In recent years, with the rapid development of the studies of cultural psychology in East Asian cultural circles, it is necessary to conduct the theoretical constructs to integrate the common psychological characteristics in East Asian cultural circle. The theoretical constructs of East Asian Cultural Psychology regard the impacts of traditional Confucian culture on East Asian culture and the individual as its core, and focus on self-construal, self-esteem, self-enhancement, collectivism, the differences of relationship and class, and the thinking of “golden mean” among the East Asians as the key constructs of the theoretical framework

    Preparation of modified whey protein isolate with gum acacia by ultrasound maillard reaction

    Get PDF
    peer-reviewedEffect of ultrasound treatment on whey protein isolate (WPI)-gum Acacia (GA) conjugation via Maillard reaction was investigated. And the physicochemical properties of the conjugates obtained by ultrasound treatment were compared with those obtained by classical heating. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis, high-performance size exclusion chromatography and fourier transform infrared spectroscopy provided evidence on the formation of the Maillard type conjugation. Compared with classical heating, ultrasound treatment could accelerate the glycation reaction between WPI and GA. A degree of graft of 11.20% was reached by classical heating for 48 h, whereas only 20 min was required by ultrasound treatment. Structural analyses suggested that the conjugates obtained by ultrasound treatment had less α-helix content, higher surface hydrophobicity and fluorescence intensity than those obtained by classical heating. Significantly lower level of browning intensity and significantly higher (p < 0.05) level of solubility (under alkaline conditions), thermal stability, emulsifying activity and emulsifying stability were observed for the conjugates obtained by ultrasound treatment as compared with those obtained by classical heating

    Quantifying evolution of soot mixing state from transboundary transport of biomass burning emissions

    Get PDF
    Incomplete combustion of fossil fuels and biomass burning emit large amounts of soot particles into the troposphere. The condensation process is considered to influence the size (Dp) and mixing state of soot particles, which affects their solar absorption efficiency and lifetimes. However, quantifying aging evolution of soot remains hampered in the real world because of complicated sources and observation technologies. In the Himalayas, we isolated soot sourced from transboundary transport of biomass burning and revealed soot aging mechanisms through microscopic observations. Most of coated soot particles stabilized one soot core under Dp &lt; 400 nm, but 34.8% of them contained multi-soot cores (nsoot ≄ 2) and nsoot increased 3–9 times with increasing Dp. We established the soot mixing models to quantify transformation from condensation- to coagulation-dominant regime at Dp ≈ 400 nm. Studies provide essential references for adopting mixing rules and quantifying the optical absorption of soot in atmospheric models.</p

    Design, Simulations, and Optimizations of Mid-infrared Multiple Quantum Well LEDs

    Get PDF
    We use eight-band k·p energy band structure model to help design novel GaInSb/AlGaInSb mid-infrared multiple quantum well (MQW) structures with an emitting mid-infrared waveband of 4-5 ”m. Simulation results suggest that the number of quantum wells has little influence on the spontaneous emission rate and gain because of no strong coupling between quantum wells and they just simply follow scaling laws. The SiLENSe software module from STR-soft is used to investigate injection efficiency of the designed MQW structures. Simulation results indicate that the MQW structures offer better carrier confinement i.e. higher carrier injection efficiency compared with traditional bulk active regions which are currently used for mid-infrared LEDs and sensors. Experimental investigations show that the MQW LEDs with a seven wells structure show an increase of a factor 2 in wall plug efficiency and output power compared with conventional bulk LEDs at the same wavelength

    Performance enhancement of phase change materials in triplex-tube latent heat energy storage system using novel fin configurations

    Get PDF
    Phase change material (PCM) has promising applications as an energy storage material in thermal energy storage (TES) systems. However, the low thermal conductivity of PCM limits its applications. To reduce the response time of TES systems, various configurations of fins are used to improve the heat transfer performance of PCM. The Y-structured fins utilize the Y-structure, a common structure in nature, and this study investigates the different structures of Y-shaped fins and the effect of HTF on melting time. A numerical research method based on the enthalpy-porosity method is adopted used for the study. The numerical model of the study is validated using previous experimental data. The simulation results have been obtained, including solid–liquid interface contours, isotherm contours, and evolution of the PCM liquid fraction. The results show that the melting process of the PCM is divided into three main stages and integrated solid fins within the PCM effectively reduce the melting time. Under certain operating conditions, reducing the fin thickness, increasing the fin angle, and increasing the HTF temperature can effectively reduce the PCM melting time. Transient heat transfer rates and dimensionless quantities are analyzed based on numerical results. This study provides potential applications of novel fin structures for new industrial products related to thermal energy storage and management

    A comparison of Antarctic ice sheet surface mass balance from atmospheric climate models and in situ observations

    Get PDF
    In this study, 3265 multiyear averaged in situ observations and 29 observational records at annual time scale are used to examine the performance of recent reanalysis and regional atmospheric climate model products [ERA-Interim, JRA-55, MERRA, the Polar version of MM5 (PMM5), RACMO2.1, and RACMO2.3] for their spatial and interannual variability of Antarctic surface mass balance (SMB), respectively. Simulated precipitation seasonality is also evaluated using three in situ observations and model intercomparison. All products qualitatively capture the macroscale spatial variability of observed SMB, but it is not possible to rank their relative performance because of the sparse observations at coastal regions with an elevation range from 200 to 1000 m. In terms of the absolute amount of observed snow accumulation in interior Antarctica, RACMO2.3 fits best, while the other models either underestimate (JRA-55, MERRA, ERA-Interim, and RACMO2.1) or overestimate (PMM5) the accumulation. Despite underestimated precipitation by the three reanalyses and RACMO2.1, this feature is clearly improved in JRA-55. However, because of changes in the observing system, especially the dramatically increased satellite observations for data assimilation, JRA-55 presents a marked jump in snow accumulation around 1979 and a large increase after the late 1990s. Although precipitation seasonality over the whole ice sheet is common for all products, ERA-Interim provides an unrealistic estimate of precipitation seasonality on the East Antarctic plateau, with high precipitation strongly peaking in summer. ERA-Interim shows a significant correlation with interannual variability of observed snow accumulation measurements at 28 of 29 locations, whereas fewer than 20 site observations significantly correlate with simulations by the other models. This suggests that ERA-Interim exhibits the highest performance of interannual variability in the observed precipitatio
    • 

    corecore